UNITED STATES DEPARTMENT OF THE INTERIOR

THE MOLLUSCAN FAUNA OF THE 

ALUM BLUFF GROUP OF FLORIDA

PART V. TELLINACEA, SOLENACEA, MACTRACEA 

MYACEA, MOLLUSCOIDEA

GEOLOGICAL SURVEY PROFESSIONAL PAPER 142-E

Please do not destroy or throw away this publication. If you have no further use 

for it, write to the Geological Survey at Washington and ask for a frank to return it

DEPARTMENT OF THE INTERIOR

Hubert Work, Secretary

U. S. GEOLOGICAL SURVEY 

George Otis Smith, Director

Professional Paper 142 E

THE MOLLUSGAN FAUNA OF THE ALUM BLUFF GROUP

OF FLORIDA

BY

JULIA GARDNER

PART v. TELLINACEA, SOLENACEA, MACTRACEA,

MYACEA, MOLLUSCOIDEA

Published June 5,1928

(Pages 185-249)

UNITED STATES

GOVERNMENT PRINTING OFFICE

WASHINGTON

1928

For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington 2.5, D. C.
CONTENTS

	Page 

Introduction.__..___._-._______________________ .__ 185

Systematic descriptions.___________________________ 189

Phylum Mollusca__-_-___-_-________.________ 189

Class Pelecypoda---_--__-_-_-___-__.______ 189

Order Teleodesmacea__________________ 189

Superfamily Tellinacea-____________ 189

Family Tellinidae___________ 189

Family Semelidae. ____________ 203

Family Donacidae___--___--___ 211

Family Psammobiidae.-.__.-___ 213

Superfamily Solenacea_____________ 216

Family Solenidae. _____________ 217

Superfamily Mactracea_____._-_.___ 218

Family Mactridae____-__-___-_ 219

Family Mesodesmatidae._______ 223

Page

Svstematic descriptions Continued. 

Phylum Mollusca Continued.

Class Pelecypoda Continued.

Order Teleodesmacea Continued.

Superfamily Myacea.__--__--______ 226

Family Corbulidae___-_--______ 226

Family Spheniopsidae._________ 236

Family Saxicavidae. ___________ 237

Family Gastrochaenidae._______ 238

Phylum Molluscoidea.-.----------------------- 239

Class Brachiopoda___---_-_-_--__-_-------_ 239

Order Neotremata.____________________ 239

Superfamily Discinacea____________ 239

Family Discinidae.____________ 239

Index.___________________________________________ i

PLATES XXIX-XXXII.

XXXIII.

XXXIV.

XXXV.

XXXVI.

ILLUSTRATIONS

Page 

TeHinacea of the Alum Bluff group ___--_-___----_---____-_-_--______ __-- 242-245

Tellinacea, Solenacea, and Mactracea of the Alum Bluff group_-_-___-----_-_-_------------ 246

Mactracea and Myacea of the Alum Bluff group ----------------------------------------- 247

Myacea of the Alum Bluff group____--------------------------------------------------- 248

Myacea and Discinacea of the Alum Bluff group-..--.----------------------------------- 249

ii
DISTRIBUTION OF THE FAUNA

The following list shows the localities cited by 

number in the text and tables:

322b. Nigger Sink, 8 miles north of Newmansville, Alachua 

County, Fla.

359. Chimney Rock Quarry, half a mile north of Gainesville, 

Alachua County, Fla.

360. Preston's marl bed, 33^ miles north of Waldo, Alachua 

County, Fla.

361. Hogtown Creek, at old mill 2 miles northwest of Gainesville, Alachua County, Fla.

365. Magnesia Springs, 4 miles northwest of Hawthorn, 

Alachua County, Fla.

369. Hammock west of Magnesia Springs, near Hawthorn, 

Alachua County, Fla.

373. Phosphate rock of the Devil's Mill Hopper, 5 miles 

northwest of Gainesville, Alachua County, Fla.

395. 50-foot well in Tallahassee, Leon County, Fla.

2116. Lapenotiere's Hammock, on Sixmile Creek, 1% miles 

south of Orient Station, Hillsborough County, Fla.

2211. Lower bed, Alum Bluff, Liberty County, Fla.

2212. Tenmile Creek, 1 mile west of Baileys Ferry, Calhoun 

County, Fla.

2213. 1 mile below Baileys Ferry, Chipola River, Calhoun 

County, Fla.

2214. Tenmile Creek, 1 mile west of Baileys Ferry, Calhoun 

County, Fla.

2238. Flournoy's Mill Race, 2 miles east of Argyle, Walton 

County, Fla.

2302. 2 miles west of Tallahassee, Leon County, Fla.

2322. Sopchoppy Creek, Wakulla County, Fla.

2324. White Sulphur Springs (White Springs), Suwannee 

River, Hamilton County, Fla.

2380. Clay Springs, Orange County, Fla.

2564. McClelland farm, 1 mile below Baileys Ferry, Calhoun 

County, Fla.

2566. Upper bed at Rock Bluff, Apalachicola River, Liberty 

County, Fla.

2568. Lower or "Chipola" bed at Alum Bluff, Apalachicola 

River, Liberty County, Fla.

2611. West bank of Suwannee River, SW. % NW. H SE. % 

sec. 8, T. 4 S., R. 11 E., near Dell, Lafayette County, and 15 

miles south of Ellaville, Madison County, Fla.

2612. West bank of Suwannee River just below a sulphur 

spring 2^2 miles below 2611, Lafayette County, 17 miles south 

of Ellaville, Madison County, Fla.

2645. McClellan farm, Shoal River, 5 miles west of Mossyhead, Walton County, Fla.

2646. Oak Grove, Yellow River, Okaloosa County, Fla.

2652. Horse Creek, 1>£ miles south of Oak Grove, Okaloosa 

County, Fla.

2653. "Otaheite beds," on east Blackwater Creek, 15 miles 

west of Oak Grove, Okaloosa County, Fla.

2675. 1 mile south of railroad bridge at Mulligan, Okaloosa 

County, Fla.

2823. West bank of Suwannee River just below sulphur 

spring 2^4 miles below 2612, 193^ miles south of Ellaville, 

Madison County, Fla.

2868. Fuller's earth bed, Quincy, Gadsden County, Fla.

3173. "Fuller's earth" mines of Chesebrough Co., Quincy, 

Gadsden County, Fla.

3385. Gastropod Gulch, 4 miles southeast of Bainbridge, 

Decatur County, Ga.

3386. Roseland Plantation, 3J^ miles southeast of Bainbridge, Decatur County, Ga.

3396. Sam Dickens's field, 7 miles southeast of Bainbridge, 

Decatur County, Ga.

3415. "Rock Bluff," east bank of Apalachicola River, 12 

miles below railroad, Liberty County, Fla.

3417. Alum Bluff, 35 miles below railroad bridge over 

Apalachicola River, Liberty County, Fla.

3419. McClelland farm 1 mile below Baileys Ferry, Calhoun 

County, Fla.

3424. J. C. Henderson's well, western limits of Tallahassee, 

Leon County, Fla.

3704. Quincy, Gadsden County, Fla.

3731. Near Mossyhead, sec. 6, T. 3 N., R. 21 W., Walton 

County, Fla.

3732. Dave Adam's MiU Creek, sec. 2, T. 3 N., R. 21 W., 

Walton County, Fla.

3733. Three-fourths mile west of Shell Bluff, Shoal River, 

Walton County, Fla.

3742. SheU Bluff, Shoal River, Walton County, Fla.

3747. 8 miles south of Lake De Funiak, Walton County, Fla.

3748. Summerville mill race, 1 mile east of Argyle, Walton 

County, Fla.

3749. Alien Senterfeit's mill, 3 or 4 miles north of Campton, 

Walton County, Fla.

3856. 6 miles west-northwest of Mossyhead, Walton County, 

Fla.

4966. 1,000 feet above Georgia, Florida & Alabama Railroad 

bridge over Ochlockonee River, Wakulla County, Fla.

4976. White Springs, Hamilton County, Fla.

4977. W. C. Rose's farm, West Sopchoppy, Wakulla County, 

Fla.

4978. Rose's Mill Creek, 3 miles west of Sopchoppy, Wakulla 

County, Fla.

4986. Miller's quarry, 1 mile from Ellenton, Manatee County, 

Fla.

4991. Ochlockonee River, 1 mile south of Holland, Leon 

County, Fla.

5079. One-half mile below Shell Bluff, Shoal River, Walton 

County, Fla.

5080. First ravine below Shell Bluff, Shoal River, Walton 

County, Fla.

5184. First ravine below Shell Bluff, Shoal River, Walton 

County, Fla.

5192. Folk's Creek, 4 miles south of Argyle, Walton County, 

Fla.

5193. Crowder's Crossing, half a mile below Shell Bluff, 

Shoal River, Walton County, Fla.

5194. Half a mile below SheU Bluff, Shoal River, Walton 

County, Fla.

5195. First ravine below SheU Bluff, Shoal River, Walton 

County, Fla.

5613. Coronet phosphate mine, 5 miles southeast of Plant 

City, Hillsborough County, Fla.

5618. Three and one-half miles southwest of De Funiak 

Springs, Walton County, Fla.

5629. Coronet phosphate mine, 5 miles southwest of Plant 

City, Hillsborough County, Fla.

in
IV DISTRIBUTION OF THE FAUNA

5630. 100 yards below Oak Grove Bridge, Yellow River, 

Okaloosa County, Fla.

5631. Oak Grove Bridge, Yellow River, Okaloosa County, 

Fla.

5632. Oak Grove, Yellow River, Okaloosa County, Fla.

5633. Oak Grove, Yellow River, Okaloosa County, Fla. 

6175. Left bank of Suwannee River three-fourths mile above 

White Springs, Columbia County, Fla.

6196. Rock stratum lying immediately above fuller's earth 

at Ellenton, Manatee County, Fla.

6197. Limestone underlying fuller's earth at Ellenton, 

Manatee County, Fla.

6208. Marl underlying phosphate of Pierce Phosphate Co., 

Pierce, Polk County, Fla.

6209. Two and one-half miles southwest of Phosphate Mining 

Co. 's pit No. 4, Mulberry, Polk County, Fla.

6769. East bank of Suwannee River at wagon bridge at White 

Springs, Hamilton County, Fla.

6775. Spring on left bank of Suwanee River about 100 yards 

above Rock Island and about half a mile above White Springs, 

Columbia County, Fla.

6776. Spring on left bank of Suwannee River about 100 

yards above Rock Island and about half a mile above White 

Springs, Columbia County, Fla.

6778. Spring on left bank of Suwannee River about 100 

yards above Rock Island and about half a mile above White 

Springs, Columbia County, Fla.

6783. Langston's Sink, about 4 miles northwest of Lake 

City, on road to White Springs, Columbia County, Fla.

6800. Preston Sink, 3 miles north of Waldo, Alachua County, 

Fla.

6801. Lochloosa Creek, near Magnesia Spring, about 3 miles 

west of Hawthorn, Alachua County, Fla.

7054. 400 feet below bridge, Oak Grove, Okaloosa County, 

Fla.

7055. Old Senterfeit mill, 4J^ miles southwest of Laurel 

Hill, Walton County, Fla.

7148. Gastropod Gulch, 5J^ miles southeast of Bainbridge, 

Decatur County, Ga.

7151. Tenmile Creek, Calhoun County, Fla.

7183. Alum Bluff (lower bed), Liberty County, Fla.

7256. Look and Tremble Shoals, Chipola River, Calhoun 

County, Fla.

7257. Sexton's Marl, Tenmile Creek, Calhoun County, Fla.

7261. Upper Alaqua Lethu (?) Bluff, near De Funiak Springs, 

Walton County, Fla.

7264. De Funiak "Cardium beds," Alaqua Creek, Walton 

County, Fla.

7468. Sopchoppy, Wakulla County, Fla.

7847. Lake Butler, Bradford County, Fla.

7893. Boynton Landing, Choctawhatchee River, Washington County, Fla.

9957. Gully south of the road and east of the bridge over 

White's Creek, on road from Eucheeanna to Knox Hill, 6.7 

miles south of Argyle, 1.7 miles southeast of Eucheeanna, 

Walton County, Fla.

9958. Site of Flournoy's old mill, about 1J^ miles northeast 

of Argyle, Walton County, Fla.

9959. One-fourth mile west by north of Pleasant Ridge 

Church, 5.2 miles southwest of De Funiak Springs, Walton 

County, Fla.

9960. Folk's Creek, sec. 21 or 22, T. 3 N., R. 18 W., 6 miles 

south of Argyle and 1.7 miles from Eucheeanna, Walton County, 

Fla.

9961. Horse Creek, 1J^ miles south of Oak Grove, Okaloosa 

County, Fla.

9994. John M. P. McClelland's farm, Chipola River, Calhoun 

County, Fla.

10596, Waldon Bridge over Bruce Creek, 5 miles west of 

Red Bay, Walton County, Fla.

10603. Gully south of the road and east of the bridge over 

White's Creek, on road from Eucheeanna to Knox Hill, 6.7 

miles south of Argyle, 1.7 miles southeast of Eucheeanna, Walton County, Fla.

10608. White's Creek, half a mile below bridge on Eucheeanna-Knox Hill road, Walton County, Fla.

10609. The Woodyard, three-fourths mile above Shell Landing, Holmes Creek, Washington County, Fla. (lower bed).

10610. The Woodyard, three-fourths mile above Shell Landing, 

Holmes Creek, Washington County, Fla. (upper limestone.)

10611. White's Creek near water's edge, half a mile below 

bridge over creek on road from Eucheeanna to Knox Hill, 6.7 

miles south of Argyle, 1.7 miles southeast of Eucheeanna, Walton 

County, Fla.

10612. Chester Spence's farm, 5 miles southwest of De 

Funiak Springs, at head of Sconter's Mill Creek, Walton 

County, Fla.

10658. Shell Bluff, Shoal River, 6 miles west-northwest of 

Mossy head, Walton County, Fla.

10659. Tanner's mill (Old Senterfeit mill), 4 miles southwest 

of Laurel Hill, Okaloosa County, Fla.

10660. Lower bed, Alum Bluff, Liberty County, Fla.

10661. Godwin Bridge over Shoal River, 5 to 6 miles northwest of Mossyhead, Walton County, Fla,

10662. Lower bed, Shoal River, between Godwin Bridge and 

Shell Bluff, 5 to 6 miles west-northwest of Mossyhead, Walton 

County, Fla.

10663. Crowder's Crossing, half a mile below Shell Bluff, 

Shoal River, Walton County, Fla.

10860. Boynton Landing, 4 miles east of Miller's Ferry, 

Washington County, Fla.

10869. Folk's Creek, 6 miles south of Argyle, Walton County, 

Fla.
THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

By JULIA GARDNER

PART V. TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA

INTRODUCTION

The fifth and final paper on the Alum Bluff Pelecypoda includes representatives of some of the more 

significant groups of the Mollusca, such as the Tellinas, maetroids, and Corbulas. Most of these fossils 

are small or of medium size, and they constitute a 

much less conspicuous element in the fauna than the 

large prionodesmacean genera, the Cardiums, or the 

venerids. The general character of the faunas of 

the three formations indicated by these highly organized groups is consistent with that deduced from the 

more primitive groups and is possibly of greater 

significance. The remarkably prolific warm-water 

Chipola fauna, the cooler-water, less diversified Oak 

Grove fauna, and the Shoal River fauna, indicating a 

persistent southern element, are all clearly recorded 

in the Mollusca under discussion.

A number of outstanding details may well be 

emphasized in even a cursory introduction. The 

Tellinas, a highly organized group, conspicuous in the 

tropical and subtropical seas to-day, are so varied in 

the Alum Bluff that the eighteen species are apportioned among seven subgenera and sections. Even 

Scissula, which is characteristically later Tertiary and 

tropical, is represented in the Chipola by two species,

though it is unknown in the later Alum Bluff. Macoma s. s., a relatively cool-water group, is present in 

the Oak Grove and Shoal River but not in the Chipola. 

The warm-water analog, Psammacoma, occurs in the 

Chipola and Shoal River but not in the Oak Grove. 

The relationship between the Alum Bluff and later 

Tertiary Semeles is particularly obvious, possibly 

because Semele is characteristically an east American 

group. Semele chipolana Dall is clearly an ancestral 

form of Semele perlamellosa Heilprin, from the Caloosahatchee Pliocene, and Semele compada Dall, from 

the Oak Grove, is genetically close to Semele carinata 

Conrad, from the Duplin and other formations of the 

Chesapeake Miocene. The Alum Bluff was a notable 

epoch of development among the maetroids. The 

earliest known Mactra is M. chipolana Dall, and Mulinia orihria is the first of its genus to be recognized 

in pre-Chesapeake formations. Panope, a characteristically cool-water genus, lived only in Oak Grove 

time. Among the Gastrochaenas, the Chipola species 

is allied to that from Bowden, Jamaica, and the Oak 

Grove species to that from the Chesapeake Miocene. 

The Alum Bluff, with its conditions of unstable 

temperature, was an epoch exceptionally favorable to 

the recording of environmental changes in a shifting

and developing molluscan fauna.

185
186 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Local distribution of species of Tellinacea, Solenacea, Mactracea, Myacea, and Molluscoidea

Jpr, prolific; a, abundant; c, common; p, present; r, rare (not more than half a dozen individuals). The localities within each State and formation are arranged in geographic 

order from north to south and from west to east. A few of the peninsular localities are not included]

[C = Cornell University. A=Aldrich collection]

Species

Tellina (Tellinella) chipolana Dall ...

(Tellinella) strophia Dall...........

(Arcopagia (Merisea)) aequistriata 

Say

(Phyllodina) leptalea Gardner,

(Eurytellina) roburina Dall ....

(Scissula) sp __ ___ ____

(Moerella) acloneta DalL. ......

(Moerella) aeosmita Dall. ......

(Moerella) ctenota Gardner, 

n. sp.._ ______ _ ......

(Moerella) acalypta Dall. ......

(Moerella) piesa Gardner, n. sp. 

Strigilla georgiana Gardner, n. sp .......

paraflexuosa Gardner, n. sp . . . __

sphaerion Gardner, n. sp. ..........

Metis chipolana DalL __________

sp-... .............................

(Psammacoma) torynoides Gard-

(Psammacoma) marmorea Gardner, 

n. sp. ___________

Semele chipolana Dall ___ _____ .

smithii Dall. .......................

mutiea Dall. .......................

stearnsii Dall. _ _________ ...

seintillata Dall... ...................

compacta Dall. __ .......

taracodes Gardner, n. sp ...........

paramutica Gardner, n. sp .........

sellardsi Gardner, n. sp _ . .........

(Semelina) cytheroidea Dall .......

(Semelina) striulata Dall. ..........

Abra cylieion Gardner, n. sp. .........

lapoehi Gardner, n. sp._..

Donax ehipolanus Dall ..........

chipolanus subsp.? eurtulus Dall...

trueloides Gardner, n. sp _ .. .

sp.. ....... .....................

(Paradonax) aldrichi (Dall MSS.) 

Gardner, n. sp __ . __ ___ .

(Paradonax) valhosierr Gardner, 

n. sp.._ __ __ __ ..... __ .

Psammobia bowdiehi Gardner, n. sp

Tagelus (Mesopleura) cf. T. divisus 

Spengler. ________________

(Mesopleura) sp ...................

Psamosolen aldrichi Gardner, n. sp

sp.. ...............................

Solen amphistemma Dall. .............

Ensis sp. ef. Ensis direetus Conrad. ...

Mactra chipolana Dall. ------ ____ .

(Maetrotoma) cymata Dall. ___ .

Spisula (Hemimactra) densa Dall

(Hemimaetra) eraspedota Gardner, 

n. sp ____ , ___ _ ...

(Hemimactra) dodona Dall

(Hemimaetra) valhosierr Gardner, 

n. sp._ ...... __ .... __ .......

Mulina orthria Gardner, n. sp

Ervilia chipolana Dall .. _ ...

chipolana subsp. triangularis Dall

condra Gardner, n. sp... ......

valhosierr Gardner, n. sp.. .........

planata Dall _ __ .... ....

Corbulaehipolana (Dall MS.) Gardner, 

n. sp_--.-. ______ _ . ......

waltonensis Gardner, n. sp ... __ .

(Caryoeorbula) sphenia Dall.. .....

(Caryocorbula) sarda Dall ....

(Caryoeorbula) franci Gardner, n. sp 

(Caryocorbula) wakullensis Gardner, n. sp __ ___ _ ....

Georgia Oak 

Grove sand

Bainbridge Near 

3 

&

P

?p

>o

00%

c

*n

00 * 

cC

'C

§ 

3

Florida Chipola formation

Woodyard The bed, Lower 

T-l

?r

P

P

Landing Boynton 

1

P

P

Ferry Bailes of milewest 1

3 

S3

P

P

....

c

Tenmile bed, marl Sexton's 

Creek

b-

>O

B

P

p

Baileys Ferr mile below 1

3 

?!

P

P

P

P

e

P

P

P

P

P

P

P

P

P

a 

P

a

N

P

P

a

a

o

i

p

pp

p

a

a

Tenmile Creek

>o 

i>

C

r

c

P

BlufE Alum bed, Lower 

t-H

H

p

'r

P

P

c

c

P

P

slp

p

p

T-l

r

r

P

to 

a

 3

1 

e*s

 s®Si

M

1

(N

g

S3

Sopchoppy Creek

c® 

1

*o

?P

a

Springs White Near

>o i~

3

OS

£CO

Florida Oak Grove sand

Grove, Yellow River Oak 

to

S<M

P

?r

P

P

P

P

pr

P

P

c

P

cq

a

P

P

i

P

r

o

....

1

P

r~

P

e

x.

03

"o

5sf-1 >

fl

8

1

5

i

a

c

southwest of<% miles 

Hill Laurel 

i

?P

P

Laurel miles southwest of4

Hill

I

P

P

P

....

north Camp- miles of34or

ton

1

CO

p

r
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 

Local distribution of species of Tellinacea, Solenacea, Mactracea, Myacea, and Molluscoidea Continued

187

Species

Corbula Continued 

(Caryocorbula) anteniae Maury ....

(Caryocorbula) .whitfieldi Dall.. ...

(Caryocorbula) whitfieldi n. subsp.

(Caryocorbula) whitfieldi n. subsp. 

boyntoni Gardner ................

(Caryocorbula) parawhitfleldi Gard-

(Caryocorbula) semenoides Gardner, n. sp ________ .. ____

(Caryocorbula) funiakensis Gard-

(Bicorbula) sp. ind. ................

(Bothrocorbula) synarmostes Dall..

(Bothrocorbula) radiatula Dall.....

Gastrochaena rotunda Dall .............

Georgia Oak 

Grove sand

Bainbridge Near 

£ 

S3

« 

§8CO

00

t-

$ 

8

Florida Chipola formation

Woodyard bed, The Lower 

I

Landing Boynton 

§ 

R

P

P

>> 

£

I '3 

n

*o

1 ^

0> 1

CM

N 

C»

P

Tenmile marlbed, Sexton's 

Creek

wCM

P

P

£

£

1 'a

n

 3 1

.a

<U

co 

§

n

a

c

P

P

 *

a

P

COi

a

P

?r

Creek Tenmile 

>o 

tp

P

Blufl bed, Alum Lower 

8

2

1

Tallahassee of miles west2

I

Creek Sopchoppy 

tSprings Near White 

w tCO

»r

§

CO

Florida Oak Grove sand

Yellow River Oak Grove, 

!

a 

P

P

P

P

o»

a 

P

P

P

^ 

SIO

P

8

CO

r

I

c

r

,>* 

a 

0

o

XI s,

11M o

.2 

1

X

i

c

southwest of ±y% miles 

Hill Laurel 

»C

1

....

Laurel miles southwest of4

Hill

g 

§

n

5

C8

O

*o 

j= 

i^* a 

§1

8 

1

S

M

O5 

g

P r

1

a P
188 THE MOLLTJSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Local distribution of species of Tellinacea, Solenacea, Mactracea, Myacea, and Molluscoidea Continued

Species

(Tellinella) strophia Dall. ......... _ ............

(Phyllodina) dodona Dall. __________

(Moerella) cloneta Dall. _________ . _

(Moerella) hypolispa Dall.. __________

(Moerella) acosmita Dall.. ...................

(Moerella) agria Dall. __ . __ .. ...

(Moerella) acalypta Dall. ....................

(Moerella) piesa Gardner, n. sp _ ... .

Strigilla georgiana Gardner, n. sp.. _ __ ....... ....

sphaerion Gardner, n. sp _ _ ____ .

Metis chipolana Dall ___________ ........

sp........ ........................................

(Psammacoma) marmorea Gardner, n. sp_. . ...

Semele chipolana Dall _____ .. _____ ...... ....

smithii Dall ________ ___ ....

mutica Dall ___ ... ___ ____ .. . _ . .

stearnsii Dall __ .. ______ ..... __ .... .. ...

scintillata Dall __ ....... __ ...................

compacta Dall . . . ___ ___ .. ___ . .

taracodes Gardner, n. sp_. ___ ........ _ .

sellardsi Gardner, n. sp... ____ ... .

(Semelina) cytheroidea Dall _ ...... . .

Florida Shoal River formation

west-northwest miles of6

Mossyhead

S00 

CO

p

p

(Semelina) striulata Dall. __________ ... ..

Abra cylicion Gardner, n. sp __ .. _ ... r

lapochi Gardner, n. sp.... __ .... _ ....... .....

Donax chipolanus Dall _ ........... _ . _ ...

chipolanus subsp.? curtulus Dall.... __ . _ .....

trueloides Gardner, n. sp. _______ . ___ ...

(Paradonax) aldrichi (Dall MSS.) Gardner, n. sp.

(Paradonax) valhosierr Gardner, n. sp..... .

Psammobia bowdichi Gardner, n. sp_ __ ....... _ .

Tagelus (Mesopleura) cf. T. divisus Spengler. ........

(Mesopleura) sp..__ ________________

Psamosolen aldrichi Gardner, n. sp... __ .. _ ......

Solen amphistemma Dall_. __ ___ __ ....

Ensis sp. cf. Ensis directus Conrad... ___ ___ _

Mactra chipolana Dall.... __ _______ .... .....

(Mactrotoma) cymata Dall. .....................

(Hemimactra) craspedota Gardner, n. sp..

(Hemimactra) dodona Dall.. ....................

(Hemimactra) valhosierr Gardner, n. sp...

Mulina orthria Gardner, n. sp. ___ ___ ... .....

Ervilia chipolana Dall... __ ............

chipolana subsp. triangularis Dall. ____ .

condra Gardner, n. sp.. ______ _ ___ .....

valhosierr Gardner, n. sp. ________ ... _ ...

planata Dall. _ ... _ ...... ______ _ . .

Corbula chipolana (Dall MS.) Gardner, n. sp. __ . .

waltonensis Gardner, n. sp_. ________ .

(Caryocorbula) sphenia Dall. ..............

(Carvocorbula) sarda Dall. ___________ ..

(Carvocorbula) franci Gardner, n. sp __ ...

(Caryocorbula) wakullensis Gardner, n. sp.

(Caryocorbula) antoniae Maury.... ___ .. .

(Caryocorbula) whitfleldi Dall. __ ..............

(Caryocorbula) whitfleldi n. subsp. stikta Gardner.--...-. __ ... _ .. __ _ ___ __

(Caryocorbula) whitfleldi n. subsp. boyntoni 

Gardner.. ___ .... __ _________ .....

(Caryocorbula) parawhitfleldi Gardner, n. sp ....

(Caryocorbula) semenoides Gardner, n. sp.

(Caryocorbula) seminella Dall. ______ . .

(Caryocorbula) funiakensis Gardner, n. sp ___ .

(Bicorbula) sp. ind.. __________ ....

(Bothrocorbula) synarmostes Dall.... ...........

radiatula Dall .......

Spheniopsis americana Dall.. ..................

Panope parawhitfieldi Gardner, n. sp ................

sp. ..............................................

Gastrochaena rotunda Dall... . __ ....

dodona Gardner, n. sp __________ _ ...

Discinisca aldrichi Gardner, n. sp_.

p

p

p

(1

«o

sM

Dave Creek Adams Mill

g

«

Shell Bluff, Shoal River

SCO

.... p

r

....

::::

....

....

....

r

p

Q

p

p

00

I

0

a 

oa

1 "aS

ua«

a

l« 

1

« 

S

%o

1

1

r

a

 I 

1*O

Yi mile below ShellBluff

i

c

3 

a 

oa

it

o

!i =« 

a

to

t*

o 

«o

3

s

P

--

....

....

P

1

....

'r

A

r

P

o

Pr

'r

?rr

pr

c

'r

c

1

1J^ miles northwest of

Shell Bluf

§IO

....

c

p

p

p

r

P

P

r

r

r

1 S

r

% Mossyhead mile ofwest

CO

RCO

_<D

5"o

1 

OJ

<o i

CM

!}/£ miles northeast Argyle of 

1

®

1<1 "5

S 

B

aCO

<o Q

0>

M 

$

°l 

A 8

IS 

w

S

a

co

3

3

§"g 

Is

<! 

tj 

&2. 

P

r~ ^

 ^ !ff P- eS

M tDe FuniakCardium beds" " 

Alaqua

S

s

p ' _ . . ...

0> "^

Cld

i<

"o

a

I

o

1M<

§S

I

'r

P

'r

r

'r

|

....

-

|

P P c

1

|

i

!

r P r

i

i1

,

| 9960 miles south Argyle of 6

1

......... ...............

i

i

'r

P

 - ! P

.... n

P r

i

r

p

P

c

i

I

P

r

P

'

i

i

P

p ] -

1

p

p

p

....

P

P

r

P

south Argyle miles of6.7

1

r

p

1 §

!

i

P ....

De miles southwest of3.5R1S ,

01)18 Funiak Sprngs

'r

r

P ....

i

C r\

'

c a a

1 <

r

c

r

a pr

r ....

9r

P

r

?P

P

c

1 southwest DeIofmiles 5mfiio 

10612 j Springs Funiak 

r

....

r

P
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 189

SYSTEMATIC DESCRIPTIONS

Phylum MOLIUSCA

Class PEIECYPODA

Order TELEODESMACEA

Superfamily TEIIINACEA Blainville

Dall,1 in 1895, gave the following description:

Siphons distinct to their bases, usually long; pallial line 

sinuate; ligament external, seated on nymphs; hinge with normally an anterior and posterior lateral in each valve, two radial 

cardinals, of which the anterior is usually bifid and somewhat 

pedunculated and the posterior, as well as the laterals, often 

obsolete.

Family TELIINIDAE Deshayes 

Genus TELLINA (Linnaeus) Lamarck

1758. Tellina Linnaeus, Systema naturae, 10th ed., p. 674. 

1799. Tellina Lamarck, Prodrome d'une nouvelle classification des coquilles: Soc. hist. nat. Paris M6m., p. 84.

Type: Tellina radiata Linnaeus. (Recent in the 

West Indies.)

Tellina virgata Linnaeus (Recent in the IndoPacific) has been commonly cited as the type of the 

genus because it is the only species mentioned by 

Lamarck in his "Prodrome." Under the present 

rules, however, this is not considered sufficient to fix 

the type. Tellina radiata was definitely designated 

in 1822 in an article entitled, "Lamarck's 'Genera of 

shells.' " 2

Shell transversely ovate to ovate-trigonal in outline, compressed; usually rostrate and flexed to the 

right posteriorly and broadly depressed in front of the 

rostrum. Umbones low, subcentral or posterior, often 

opisthogyrate. External surface rarely smooth; dominant sculpture concentric, regular, and, as a rule, 

more or less incremental in character; radial ornamentation commonly suggested by the color pattern and 

by the reinforcing internal rays, rarely by the sculpture; oblique sculpture developed in one group. Ligament external, opisthodetic. Two cardinals, one of 

them bifid, developed in each valve, interlocking in the 

closed valves so that the bifid teeth are flanked on 

either side by a simple laminar tooth. Anterior and 

posterior laterals developed in some groups in both

Latitude of adult exceeding 15 millimeters:

External surface closely, sharply, and regularly threaded: 

Shell transversely elongated:

Altitude of adult more than half the latitude..-- _____________________________ Tellina (Tellinella) chipolana Dall.

Altitude of adult less than half the latitude.____________________________________ Tellina (Tellinella) strophia Dall.

Altitude of adult approximately half the latitude...._._.___....__. .Tellina (Tellinella) waltonensis Gardner, n. sp.

Shell ovate-trigonal._______________________________________________ Tellina [Arcopagia (Merisca)] aequistriata Say.

External surface not closely, sharply, and regularly threaded:

Valves strikingly dissimilar; the right valve conspicuously flattened:

Right valve sharply but not closely sculptured concentrically; sculpture of left valve irregular and undulatory in 

character, strongest near the umbones___________________________7Wfo'rca [Arcopagia (Phyllodina)] dodona Dall.

Right valve feebly sculptured anteriorly and medially; sculpture of left valve sharply raised posteriorly, more or 

less flattened medially and anteriorly______________ ...Tellina [Arcopagia (Phyllodina)] leptalea Gardner, n. sp.

Valves not strikingly dissimilar; the right valve only slightly less convex than the left; both valves sculptured with fine, 

flattened, closely overlapping lamellae.____________________________ Tellina [Arcopagia (Eurytellina)] roburina Dall.

' Dall, W. n., Contributions to the Tertiary fauna of Florida: Wagner Free Inst. Sci. Trans., vol. 3, pt. 3, p. 553, 1895.

2 Roy. Inst. Great Britain Quart. Jour. Sci., Literature, and the Arts, vol. 14, p. 306, 1822. The series of articles of which this is the first was published anonymously but later appeared in book form under the name of John George Children.

X<)7l!«i O 50 2 (112-K)

valves; in others, reduced to a single right anterior 

lateral. Sinus free or coalescent ventrally with the 

pallial line, often discrepant in the two valves, the 

dorsal margin of the sinus commonly uniting the 

anterior and posterior adductors.

Though the type of the genus is a West Indian 

shell, Tellina s. s. has not been recognized in the Alum 

Bluff fauna.

The Tellina fauna of the Alum Bluff group is more 

remarkable for the number of species than for the number of individuals. None of the 18 species represented are really abundant, and most of them are rather 

rare. All of them, apparently, are short-lived and 

restricted in the Alum Bluff to the single horizon at 

which they are found, though a few have close analogs at other horizons. The Chipola formation has 

yielded 11 out of the 18 species, a little more than 60 

per cent, the Oak Grove sand 4, and the Shoal River 

formation 3, though at both the upper and middle 

horizons there are at least two additional species, too 

imperfectly preserved to warrant description. Two of 

the three Tellinella occur in the Chipola, the third in 

the Shoal River. Arcopagia (Merisca) aequistriata, 

has been reported from the lower beds at Alum Bluff, 

but there is a possibility that the form may have come 

from higher up in the section. No trace of this 

species has been found in either the Oak Grove or the 

Shoal River. Arcopagia (Phyllodina') has a representative in the Oak Grove and another in the Shoal 

River, but it has not been recognized in the Chipola. 

Arcopagia (Eurytellina) roburina Dall is the most conspicuous member of the genus in the Oak Grove fauna, 

while the only other Alum Bluff Eurytellina is known 

only from the type specimen. Both species of Arcopagia (Scissula), one of them too imperfect to be 

named, are restricted in their known distribution to 

the Chipola. Eight species, most of them described 

under Angulus, are referred to Moerella. Of these, 

five are restricted to the Chipola and two to the Oak 

Grove; piesa is the only Tellina of common occurrence in the Shoal River. The diversity of this highly 

organized group of Mollusca is one of the most modern 

features of the Alum Bluff fauna.
190 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Latitude of adult valve not exceeding 15 millimeters:

Altitude of shell decidedly more than half the latitude:

Shell conspicuously flattened, subelliptical in outline..................--Tellina [Arcopagia (Eurytellina)] pressa Dall.

Shell ovate-trigonal in outline, not flexuous nor conspicuously flattened:

Shell thin, lustrous, the sharp concentric threading developed over the greater part of the external surface.

Tellina (Moerella) cloneta Dall. 

Shell rather heavy, dull, the sharp concentric threading restricted for the most part to the ventral margins.

Tellina (Moerella) hypolispa Dall. 

Shell flexuous, smooth, except for incrementals_-_--_--_---_--------------_------_--TeMwa (Moerella) acloneta Dall.

Altitude of shell approximately half the latitude: 

Surface sculpture not oblique:

Surface very finely sculptured concentrically:

Sculpture irregularly developed_______________________________________ Tellina (Moerella} acosmita Dall.

Concentric threading microscopically fine but developed over the entire external surface:

Shell rather sharply rostrate_______-__-___-__--------------_--_--------7W?wa (Moerella) agria Dall.

Shell obtusely rostrate_______-____--______--___-_-------_-__ Tellina (Moerella) ctenota Gardner, n. sp.

Surface sculpture absent or reduced to a microscopically fine lamination:

Shell relatively inflated_____-______-____-___-__-__----____-_-___-__ ...Tellina (Moerella) acalypta Dall.

Shell relatively compressed._______________________________________ Tellina {Moerella) piesa Gardner, n. sp.

Surface sculpture oblique._________________________________ ..........Tellina [Arcopagia (Stissula)] lampra Dall.

Subgenus TELLINELLA Morch

1853. Tellinella Morch, Catalogus conchyliorum, Comes de 

Yoldi, vol. 2, p. 13.

Type: Tellina virgata Linnaeus. (Recent in the 

Indo-Pacific.)

Tellina was credited by Morch to "Gray, 1852." 

The name may have been taken from a manuscript 

label, but no mention of it can be found in any of 

Gray's published papers. The type was selected by 

Meek.3

Shell subequivalve; transversely ovate to ovatetrigonal in outline; posteriorly rostrate. Umbones 

low, subcentral, feebly opisthogyrate. Sculpture concentric, lirate, or laminar. Ligament external, elongated parallel to the dorsal margin. Two cardinals 

and anterior and posterior laterals developed in each 

valve, the left laterals, however, often nothing more 

than the modified dorsal margins. Pallial sinus very 

deep but only partially coalescent ventrally with the 

pallial line, its dorsal extremity falling short of the 

anterior adductor.

Tellina (Tellinella) chipolana Dall

Plate XXIX, Figure 1 

1900. Tellina chipolana Dall, Wagner Free Inst. Sci. Trans.,

vol. 3, pt. 5, p. 1018, pi. 47, fig. 6.

Not Tellina chipolana Dall, U. S. Nat. Mus. Bull. 90, 

p. 151, pi. 22, figs. 1, 2, 1915.

Dall described this species in 1900, as follows:

Shell solid, ovate, inequilateral, the anterior side longer, 

beaks low, pointed; anterior end rounded, rather plump, posterior end more compressed, rostrate, strongly folded, dorsal 

area with two radial ridges, each with a shallow sulcus above 

it, posterior angle obliquely truncate; surface with obscure, 

fine radial striation, sculptured with strong, low, sharp, regular, 

elevated, concentric lamellae; hinge normal, left laterals obscure, lunule impressed, narrow, smooth; interior with an

3 Meek, F. B., A report on the invertebrate Cretaceous and Tertiary fossils of the 

upper Missouri country: U. S. Geol. Survey Terr. Kept., vol. 9, p. 193,1876.

obscure thickened ray behind the anterior adductor scar; pallial sinus low, ovate, about half confluent below. Longitude 

38, altitude 23, diameter 11 millimeters.

The left valve is very sharply pointed and flexed behind. 

This form may be regarded as a precursor of such types as T. 

interrupta Wood, of the recent fauna.

Type: U. S. Nat. Mus. No. 114596.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

The valves are pulled down at the posterior basal 

angle and the base line constricted in front of it. The 

concentric laminae follow the outline of the base and 

are most elevated upon the dorsal ridges. Because 

of the relatively thick shell the characters of the interior are unusually distinct. The adductor scars are 

rudely semielliptical in outline and set very close to 

the lateral margins. The dorsal margin of the pallial 

sinus lies well up toward the beaks, quitting the posterior adductor at the upper inner angle. The pallial 

line is very close to the base.

There is no coexistent species with which this fine 

shell can be confused. The Chipola species is a 

smaller, less flexuous shell than that from Ballast Point 

with lower posterior rays, a somewhat finer, sharper 

concentric sculpture, and a rather distinct umbonal 

ornamentation. In T. chipolana the sculpture is uniform in character from the tips of the umbones to the 

basal margin, a rather fine and sharp concentric lamination with crowded microscopic radial striae in the 

interspaces. In the Ballast Point species, on the contrary, the concentric laminae are much lower and more 

distant near the tips of the umbones, and the interspaces are threaded with about half a dozen exceedingly fine and crowded concentric lirae. This sculpture persists until the shell is between 1 and 2 millimeters in altitude.

Occurrence: Chipola formation, localities 2213r, 

2211 P, 7183P, 10660r.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 191

Tellina (Tellinella) strophia Dall 

Plate XXIX, Figure 2

1900. Tellina strophia Dall, Wagner Free Inst. Sci. Trans., vol. 

3, pt. 5, p. 1019, pi. 47, fig. 11.

Dall describes this species as follows:

Shell elongate, subequilateral, slender, with inconspicuous 

beaks, rostrate, and sharply sculptured, with low, elevated, 

close-set concentric lamellae, which become sparser and more 

prominent on the posterior part of the shell, especially on the 

rostrum; posterior dorsal area with two radial folds separated 

by a shallow sulcus, the upper fold obscure; lunule very narrow, moderately impressed; rostrum of the left valve ending 

in a narrow sharp point; teeth normal, small; in the left valve 

obscure; pallial sinus elongate, two-thirds confluent below, 

rounded behind. Longitude 27, altitude 11, diameter 5 millimeters, but probably reaching a size one-third greater, judging 

by fragments collected.

This shell recalls T. cumingii, though smaller and more delicate.

Type: U. S. Nat. Mus. No. 114659.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla. The 

species is known only from the type locality and has 

not been recognized in any of the later collections.

Occurrence: Chipola formation, locality 2213P .

Tellina (Tellinella) waltonensis Gardner, n. sp. 

Plate XXIX, Figures 3-5

Shell rather small for the group, thin, moderately 

compressed, transversely elongated, semielliptical in 

front of the beaks, shorter behind, slightly produced 

at the posterior basal angle with a very short vertical 

truncation near the base. Umbones small, not prominent, set behind the median line. Lunule linear. 

Escutcheon simulated by the modification of the dorsal edges. Anterior dorsal slope very gentle, the anterior extremity broadly and smoothly rounded. Posterior dorsal slope steeper and less regular. Base line 

horizontal medially, very gently upcurved anteriorly, 

slightly constricted in front of the posterior dorsal 

ray. Dorsal ridge narrow, obtuse, with a broad and 

ill-defined sulcus in front of it; a second ray nearer to 

the dorsal margin and terminating at the upper angle 

of the vertical truncation, suggested but not clearly 

defined. External sculpture on the anterior and medial 

portions of the shell of closely overlapping concentric 

lamellae not far from 50 in number, the free dorsal 

edges gradually developing on the posterior portion 

into raised threadlets; dorsal ray emphasized by the 

abrupt disappearance upon it of the alternate threadlets, the remaining lirae persisting and bent sharply 

upward hi crossing the second incipient ray. Ligament groove narrow, produced. Dentition normal; 

a short, simple, laminar anterior cardinal and a short, 

rather stout bifid posterior cardinal in the right valve, 

with a similar bifid anterior and a simple posterior 

cardinal in the left; lateral sockets developed on 

either side of the umbo of the right valve to receive

the modified dorsal edges of the left. Interior feebly 

rayed; the adductor and pallial scars obscure. Adductor scars large, set close to the lateral margins. 

Pallial sinus very large, apparently not coalescent 

throughout its ventral extent.

Dimensions: Eight valve (cotype), altitude, 10.5 

millimeters; latitude, 21.3 millimeters; semidiameter, 

2.6 millimeters. Left valve (cotype), altitude, 9.5 

millimeters; latitude, 18.5 millimeters; semidiameter, 

2.5 millimeters.

Cotypes: U. S. Nat. Mus. No. 353912.

Type locality: No. 3733, three-fourths of a mile 

west of Shell Bluff, Shoal River, Walton County, Fla.

Tellina waltonensis shares with T. chipolana Dall 

and T. strophia Dall, of the Chipola fauna, the general 

characters of the outline and ornamentation. It is 

smaller than either of the Chipola species, and the 

posterior rays are less strongly developed. In relative 

dimensions it stands approximately midway between 

the two forms mentioned, the altitude of T. waltonensis 

being about half as great as the latitude, whereas in 

T. chipolana it is decidedly more than half, and in T. 

strophia Dall decidedly less.

Occurrence: Shoal River formation, locality 3733P.

Subgenus ARCOPAGIA (Leach MS.) Thomas Brown

1827. Areopagia (Leach MS.) Thomas Brown, Illustrations 

of the conchology of Great Britain and Ireland, 

pi. 16, fig. 8.

Type: Tellina crassa Pennant. (Recent on the 

Celtic and boreal coasts of Europe and extending, in 

the Pleistocene, as far south as Sicily.)

Dall,4 in 1900, gave the following description:

Shell large, solid, rounded, moderately convex, the flexure 

obsolete; porterior left lateral absent, and the anterior obsolete, 

other teeth normal; sinus free, ascending obliquely; internal 

radii thick and strong but ill defined; sculpture concentric, 

usually smoothish or not sharply lamellate, sometimes reduced 

to incremental lines. Warm, temperate, and tropical seas.

The chief feature of this group is the free sinus, but this in 

species otherwise closely allied becomes more or less confluent.

Section MERISCA Ball 

1900. Merisca Dall, U. S. Nat. Mus. Proc., vol. 23, p. 290.

Type: Tellina crystallina (Chemnitz) Wood. (Recent in the West Indies and on the west coast from 

Lower California to Panama.)

Dall describes this section as follows:

This group comprises more or less trigonal, usually rather 

convex shells of small or moderate size, with lamellose concentric sculpture and often fine radial lines in the interspaces. There is a narrow but sharp posterior flexure; the 

laterals of the right valve are strongly developed, but the left 

valve is without lateral teeth, its margin fitting above the 

laterals of the opposite valve. The pallial sinus is ample, 

frequently wholly confluent below, and always largely confluent, the dorsal portion often represented only by a line 

connecting the adductors.

* Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 1011, 1900.
192 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

These shells are related to Macaliopsis, from which they differ 

in the absence of lateral teeth in the left valve; to Moerella, 

from which the sculpture and posterior fold separate them; 

and to Pseudarcopagia, which is not rostrate nor folded, while 

its radial sculpture is more conspicuous. The recent species 

are usually pale, without color markings, or white, and inhabit 

the warmer seas.

Tellina (Merisca) aequistriata Say 

Plate XXIX, Figure 6

1824. Tellina aequistriata Say, Acad. Nat. Sci. Philadelphia 

Jour., 1st. ser., vol. 4, p. 145, pi. 10, fig. 7.

1896. Tellina aequistriata Say. Harris, Bull. Am. Paleontology, vol. 1, No. 5, p. 321, pi. 29, fig. 7.

1900. Tellina (Merisca) aequistriata Say. Dall, TJ. S. Nat. Mus. 

Proc., vol. 23, p. 293.

1900. Tellina (Merisca) aequistriata Say. Dall, Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 5, p. 1020.

1904. Tellina aequistriata Say. Glenn, Maryland Geol. Survey, 

Miocene, p. 297, pi. 72, fig. 13.

Say, in 1824, described this species as follows:

Shell transversely ovate-orbicular, with an elevated line or 

fold on the anterior margin; surface with fine, somewhat 

elevated, concentric, nearly equal, numerous striae, forming 

grooves between them; apex nearly central, acute: cardinal 

teeth deeply grooved; lateral teeth two; edge within, simple.

Length seven-tenths, breadth nineteen-twentieths of an inch.

In general outline, this species has a resemblance to T. 

ostracea, Lam. In one specimen the apex is central, and in 

another it is placed before the middle.

The shell described by Say was supposedly collected 

in Maryland, but it seems much more probable that 

the Tellina, together with a number of other species 

from the same collection, came from Yorktown, Va. 

The type has apparently been lost.

Shell ovate-trigonal, the dorsal margins oblique 

and meeting at an angle of approximately 120°. 

Anterior portion of the valves somewhat inflated, 

contracted in front of the narrow but pronounced 

posterior (not anterior) fold. Anterior end of shell 

broadly rounded. Posterior cuneate. Ventral margin not arched. Umbones low, sharp, slightly posterior. External sculpture of 60 to 75 sharply 

elevated, concentric lamellae, approximately uniform 

in size and spacing. Ligament seated on rather short 

and narrow nymphs. Cardinals of both right and 

left valves and laterals of right strong and clean-cut; 

no true laterals developed in left valve, the function 

being performed by slightly modified dorsal margins. 

Anterior muscle scar elongated. Posterior semielliptical. Sinus usually effaced, in perfectly fresh individuals seen to be confluent ventrally with the pallial 

line. Dorsal margin irregularly sinuous, ascending 

rather abruptly from the posterior muscle impression to a point underneath the umbones and then 

descending more gradually to meet the pallial line 

just behind its juncture with the anterior muscle 

impression.

There is no positive evidence that the Tellina aequistriata reported from the lower bed at Alum Bluff were

collected from the upper bed, and yet it seems strange 

that this unusually well-preserved species has not 

been recognized in any of the later collections.

Occurrence: Chipola formation, locality ?2211r.

Outside occurrence: Miocene: Yorktown formation, Virginia; Duplin formation, North Carolina. 

Pliocene: Waccamaw formation, South Carolina; 

Croatan formation, North Carolina. Recent: North 

Carolina to Brazil hi moderate depths.

Section PHYLLODINA Dall 

1900. Phyllodina Dall, IT. S. Nat. Mus. Proc., vol. 23, p.290.

Type: Tellina squamifera Deshayes. (Recent on 

the east coast from Hatteras to the West Indies.)

A section reserved for those species which combine 

the transversely ovate outline of Phylloda with the free 

pallial sinus of Arcopagia.

Tellina (Phyllodina) dodona Dall 

Plate XXIX, Figures 7-11

1898. Tellina dodona Dall, Wagner Free Inst. Sci. Trans., vol.

3, pt. 4, p. 925, pi. 30, fig. 7 (no description). 

1900. Tellina dodona Dall, idem, vol. 5, p. 1023.

Dall, in 1900, described this species as follows:

Shell elongate, rather rude, solid, subequilateral, inequivalve, 

the right valve flatter; beaks low, compressed, with pustular 

apex and small, smooth nepionic shell; anterior part produced 

and rounded, passing evenly into the curve of the base; posterior end slightly rostrate, with a straight dorsal slope, the end 

nearly vertically truncate, the posterior basal angle in the left 

valve, pointed and produced; surface marked with rather irregular incremental lines, a conspicuous sulcus from the umbo 

radiating to a point just above the posterior basal angle; disk 

with a succession (up to 10) of low, rather obscure, concentric 

waves, obsolete distally but indicated by a sparse series of small 

triangular foliations on the posterior dorsal border, the anterior 

border being only obscurely waved; lunule long and very narrow; hinge normal, pallial sinus short, free, obliquely ascending; 

sculpture of the right valve similar but sharper, more emphatic, 

and the foliations more conspicuous. Longitude 34, altitude 21, 

diameter 6 millimeters. Longitude of figured specimen, 16 

millimeters.

Since the young valve was figured, a considerably larger left 

valve has come to light, from which, and from fragments of the 

right valve, the above description has been drawn.

Cotypes (left valves): U. S. Nat. Mus. No. 107391. 

Topotype (right valve): U. S. Nat. Mus. No. 353913.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

A very fine right valve probably referable to this 

species has been found at Oak Grove. The general 

effect of the sculpture is strikingly distinct from that 

of the left valve. Instead of the low, broad, concentric 

waves evanescing ventrally there are acutely elevated 

ridges, 13 in number, rather regular in spacing, though 

slightly broader toward the umbones. On crossing 

the dorsal ray these ridges dip sharply toward the 

base. On the dorsal sulcus they are almost or altogether obsolete but reappear at the margin and extend 

slightly beyond it, thus lending to it a finely crenate
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 193

outline. The shell is very flat and rather thin, so that 

the sculpture, both concentric and radial, is reflected in 

the interior. The simple anterior and bifid posterior 

cardinals are short but sharp, and the laterals are elevated medially, the anterior a little the stronger of the 

two. Unfortunately this lovely species is rather rare.

Dimensions of figured right valve: Altitude, 17 

millimeters; latitude, 27 millimeters; semidiameter, 

1.5 millimeters.

There is no described form which approaches it very 

closely.

Occurrence: Oak Grove sand, localities 2646P, 

5632 r.

Tellina (Phyllodina) leptalea Gardner, n. sp.

Plate XXIX, Figures 12-14

Shell of moderate dimensions for the group, compressed, inequivalve, inequilateral, exceedingly fragile; 

right valve almost flat; the left feebly convex. Umbones low, acutely pointed at the tips, orthogyrate, 

often with the minute, more inflated prodissoconch 

still preserved; umbonal angle not far from 135°. 

Lunule and escutcheon sublinear, wedging out 

altogether at the umbones. Anterior and posterior 

dorsal slopes nearly equal, the posterior a little less 

gentle. Anterior extremity very broadly and smoothly 

rounded. Base line horizontal medially, gently upcurved anteriorly, flexuous posteriorly. Posterior 

area set off in the left valve by a feeble ray terminating at the posterior basal angle, emphasized less by its 

elevation than by the character of the sculpture and 

by the constriction both in front of it and behind; a 

second broader and more elevated ray occupying 

almost the entire posterior area and widening toward 

the outer margin; a single broad ray developed in the 

right valve, terminating just behind the posterior 

basal angle, outlined by a shallow sulcus in front of it 

and a deeper sulcus behind. External sculpture concentric, dissimilar upon the two valves and also upon 

the anterior and posterior portions of the same valve; 

tips of umbones smooth in both valves except for incremental striae; three or four low, broad, acutely 

A-shaped ridges developed near the umbones similar 

to those on the right valve of T. dodona Dall; a rather 

close concentric liration developed over the greater 

part of the shell; the lirae flattened into overlapping 

laminae on the anterior medial portion of the left 

valve and over almost the entire area in front of the 

umbones on the right, raised again near the anterior 

ventral margin of the left valve of the adult and at the 

extreme anterior margin of both valves in the young 

and the right valve of the adult; posterior half of shell 

much more sharply sculptured, the lirae appearing in 

the right valve as free lamellae which persist with uniform elevation to the lunular margin, where they culminate in foliaceous processes which dentate the margin ; lirae in the left valve sharply down-curved along 

the posterior rib, the alternating lirae tending to disappear upon it; remaining lirae persistent to the dorsal 

margin, not elevated as in the right valve though culminating at the margin of the escutcheon in scabrous 

processes. Lunule and escutcheon smooth excepting 

for incrementals. Ligament external, opisthodetic, 

linear. Dentition delicate; a short, simple, laminar 

anterior cardinal and a short, bifid posterior in the 

right valve and a bifid anterior and simple posterior 

cardinal in the left; deep lateral sockets developed on 

either side of the umbones in the right valve to receive 

the modified dorsal margins of the left. Interior somewhat reinforced laterally. Adductor scars rather large, 

set close to the dorsal margins. Pallial line obscure, 

rather close to the base; pallial sinus large, ovate, 

quitting the dorsal margin of the adductor and reaching 

about two-thirds of the distance across to the anterior 

margin; ventral margin of the sinus free throughout 

its extent, joining the base at an acute angle.

Dimensions: Left valve (type), altitude, 16 millimeters; latitude, 28.5 millimeters; semidiameter, 3.5 

millimeters. Right valve (topotype, immature shell), 

altitude, 10 millimeters; latitude, 17 ± millimeters; 

semidiameter, 2.2 millimeters.

Type: U. S. Nat. Mus. No. 353914. Topotype: 

U. S. Nat. Mus. No. 353915.

Type locality: Shell Bluff, Shoal River, Walton 

County, Fla.; collected and deposited in the U. S. 

National Museum by Truman H. Aldrich.

The other member of the section Phyllodina, T. 

dodona Dall, is a larger and heavier shell, higher relatively and with a different type of sculpture.

Occurrence: Shoal River formation, localities 3856P ,

3742P .

Section EURYTEIIINA Fischer

1887. Eurylcllina Fischer, Manuel de conchyliologie et de paleontologie conchyliologique, p. 1147.

Type: Tellina punicea Born. Born cited no locality, 

but his excellent figure indicates the tropical east 

Atlantic species commonly known as T. angulosa 

Gmelin. The references of T. punicea to the west 

American coast are probably incorrect.

Dall, 5 in 1900, described this section as follows: 

Valves compressed, flexure obsolete or absent, the surface 

feebly concentrically sculptured, a radial rib behind the anterior adductor scars, the left posterior lateral lamina obsolete or 

absent, the anterior laterals adjacent, the pallial sinus close to 

or touching the anterior adductor scar and (in the type) wholly 

coalescent below with the pallial line. Tropical and warmtemperate seas.

» Dall, W. II., Contributions to the Tertiary fauna of Florida: Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 1013, 1900.
194 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Tellina (Eurytellina) roburina Dall 

Plate XXIX, Figure 15

1900. Tsllina (Eurytellina) roburina Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 1024, pi. 47, fig. 9.

Dall describes this species as follows:

Shell solid, subequilateral, rather elongate4rigonal, compressed; 

anterior end evenly rounded, posterior end pointed with a 

small truncation near the tip; beaks inconspicuous, pointed; 

lunule short and nearly linear; dorsal slopes nearly rectilinear; 

surface of the disk polished, closely, evenly, concentrically 

grooved sublamellose on the posterior dorsal area, which exhibits an obsolete fold and slight flexuosity; hinge as in Angulus, 

teeth well developed; valve thickened on the inner margin of 

the adductor scars; pallial sinus elongate, low, squarish at the 

anterior end where its distal angle nearly touches the adductor 

scar, wholly confluent below. Longitude 39, altitude 22.5, 

diameter 8 millimeters.

This is a fine species, a precursor of T. angulosa Gmelin, 

T. rubescens Hanley, and similar recent forms.

Type: U. S. Nat. Mus. No. 135893.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Tellina roburina Dall is the largest and probably 

the most abundant of the Oak Grove Tellinas. In the 

adult state there is no species with which it can be 

readily confused. T. alternata Say of the Pliocene 

and Recent faunas has the same general characters, 

though it is a larger shell and higher relatively as 

well as absolutely.

The type of the section, T. angulosa Gmelin, is 

also a possible descendant, but it is higher relatively 

and more nearly equilateral. The right laterals are 

stronger in the Miocene species than in either of the 

Recent forms mentioned, and the anterior lateral of 

T. roburina is farther removed from the cardinals 

than in either T. angulosa or T. alternata.

The young of T. roburina are very similar at first 

glance to the adult T. acalypta Dall. They may be 

distinguished by the more compressed shell, the more 

produced and conspicuous ligament area, and the 

coarser sculpture upon the dorsal area, which, however, 

is irregular like that of T. acalypta.

Occurrence: Oak Grove sand, localities 2646C , 

5632r, 5630P, 5633r, 7054r.

Tellina (Eurytellina) pressa Dall 

Plate XXIX, Figure 16

1900. Tellina (Angulus) pressa Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1026, pi. 47, fig. 5.

Dall describes this species as follows:

Shell thin, compressed, inequilateral; beaks low, hardly 

interrupting the dorsal profile, but sharp and almost pustular; 

ligament rather long, hinge delicate but normal; surface 

polished, with rather distant, fine, concentric impressed lines; 

the posterior dorsal slope with sparse, sharp, little elevated 

concentric lamellae; near the beaks the shell is smooth; interior 

with a faint anterior elevated ray which separates the adductor 

scar from the anterior part of the long, high pallial sinus, which

is wholly confluent below; the interior more or less obscurely 

radially striate. Longitude 12.5, altitude 7.5, diameter 2 

millimeters.

A thin and delicate species with no observable flexure or 

ridge on the posterior end, and whose especial characteristic 

is the high dorsal profile behind the beaks.

Type: U. S. Nat. Mus. No. 114664.

Typeloc ality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

The imperfect type remains unique. The crushed 

left valve from the Bowden, which was referred to 

this species, lacks the characteristic outline and sculpture of the Chipola species and has since been described 

by Woodring under Tellina (Eurytellina) spiekeri 

Woodring.

In the same monograph Woodring 6 indicates the 

error of referring to Angulus the numerous small 

species with a well-defined right posterior lateral, 

which have commonly been included under that subgenus. TeUina lanceolata Linnaeus, the type of the 

subgenus, is an Indo-Pacific species in which only a 

single lateral, the right anterior, is developed, and 

this, instead of being normal to the hinge plate, is 

rather an extension of it, thickened and upturned at 

the ventral extremity.

Occurrence: Chipola formation, locality 2213 r.

Section SCISSUIA Dall

1900, November. Scissula Dall, U. S. Nat. Mus. Proc., vol.

23, p. 291. 

1900, December. Scissula Dall, Wagner Free Inst. Sci. Trans.,

vol. 3, pt. 5, p. 1014.

Type: TeUina decora Say. (Recent on the east 

coast from South Carolina to Venezuela. Caloosahatchee Pliocene of Florida.)

Dall gives the following characterization:

Surface with fine oblique grooving, not in harmony with the 

incremental lines.

Tellina (Scissula) lampra Dall 

Plate XXX, Figure 11

1900. Tellina (Scissula) lampra Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1028, pi. 46, fig. 14.

Dall describes this species as follows

Shell solid, polished, moderately convex, subequilateral; 

anterior part slightly longer, rounded, posterior attenuated, 

rather bluntly pointed; beaks low, posterior dorsal area with 

delicate imbricated sculpture; disk with fine, close, sharp striations descending obliquely backward from the anterior dorsal 

margin toward the base; hinge normal, delicate; internal thickened rays in the right valve, the anterior touched by the anterior 

end of the pallial sinus, which is wholly confluent below. Longitude 8.6, altitude 7.3, diameter 4 millimeters.

This recalls T. decora Say, which is more inequilateral and 

has a blunter and differently shaped posterior end. The 

oblique sculpture also is differently disposed and more close 

set.

6 Woodring, W. P., Miocene mollusks from Bowden, Jamaica: Carnegie Inst. 

Washington Pub. 366, p. 169, 1925.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 195

Ball's figure is rather deceptive. The posterior 

extremity of the type is broken away, and he has 

figured only the earlier two-thirds of the shell. The 

altitude (7.3 millimeters) is that of the figured portion. 

The latitude is obviously an error. The altitude of 

the type is 9.5 millimeters, the longitude of the figured portion 14, though the length of the perfect 

shell was probably between 17 and 18 millimeters.

Type: U. S. Nat. Mus. No. 114600.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

No further representatives of this interesting species 

have been recognized in the later collections. The 

fragments from Boynton Landing referable to this section indicate a species three times the dimensions of 

T. lampra.

Occurrence: Chipolaformation,localities2212 r,2213 r, 

221P.

Tellina (Scissula) sp.

A very fine species from the marls at Boynton Landing is represented by a couple of fragments. They 

indicate a thin shell nearly 3 centimeters high and 

perhaps half again as broad. The concentric laminae 

are low and closely overlapping the dorsal edges, free, 

and obliquely directed at a low angle to the base. 

The adductor scars and the fragment of pallial line 

are distinct, and the ventral portion preserved is finely 

and h regularly rayed.

Occurrence: Chipola formation, locality 7893 r.

Subgenus MOERELLA Fischer

1887. Moerella Fischer, Manuel de conchyliologie et de paleontologie conchyliologique, p. 1147.

Type: Tellina donacina Linnaeus. (Recent off the 

European coasts from the Hebrides to the Mediterranean. Fossil in the Coralline Crag of England.)

Shell rather small for the genus, transversely ovate, 

obscurely rostrate posteriorly. Sculpture dominantly 

concentric, the recent species often rayed with colors. 

Umbones low, opisthogyrate. Lunule and escutcheon 

extremely narrow, indicated but not well defined. 

Ligament external, opisthodetic. TWTO cardinal teeth 

in each valve, the anterior right and the posterior left 

simple and laminar, the posterior right and the anterior 

left stouter and bifid. True laterals not developed in 

the left valve, though the edges are beveled to function 

as laterals and are received within the lateral sockets 

of the right valve; the anterior lateral more elevated 

and closer to the umbone than the left. Pallial sinus 

confluent ventrally with the pallial line throughout the 

greater part of its extent.

Most of the Alum Bluff Tellinas referred in earlier 

publications to Angidus seem more closely allied to 

Moerella. Angulus is an Indo-Pacific group in which 

only a single lateral, the right anterior, is developed; 

it has not been recognized in the lower Miocene faunas 

of the east coast.

Tellina (Moerella) cloneta Dall

Plate XXX, Figures 1-2 

1900. Tellina (Macaliopsis) cloneta Dall, Wagner Free Inst. Sci.

Trans., vol. 3, pt. 5, p. 1020, pi. 46, fig. 8. 

1900. Macoma? calhounensis Dall, idem, p. 1046, pi. 47, fig. 10.

Dall describes this species as follows:

Shell small, thin, inequilateral, anterior end longer, more 

convex, and evenly rounded; posterior end shorter, rather suddenly pointed, and slightly flexed; beaks pointed, smooth, 

prominent; lunule and escutcheon obsolete; disk without radial 

striae, but with very thin, regular, rather distant concentric, 

elevated lamellae, easily worn off, the posterior end with an 

obsolete radial fold; hinge normal, pallial sinus large, gibbous, 

nearly reaching the anterior adductor scar,, more than half 

confluent below. Longitude 13.5, altitude 8.5, diameter 4 

millimeters.

Much more delicate and of a different form from the preceding species [Tellina merula Dall].

Type: U. S. Nat. Mus. No. 114667.

Type locality: No. 2213,1 mile below Baileys Ferry, 

Chipola River, Calhoun County, Fla.

Macoma? calhounensis was described from a single 

left valve (U. S. Nat. Mus. No. 114669) from Chipola 

River. Without doubt, this is identical with Tellina 

cloneta.

Tellina cloneta is similar in general aspect and type 

of sculpture to T. hypolispa Dall, from Alum Bluff. 

The species from Chipola River is more elongated 

transversely, decidedly thinner, and more lustrous 

than the Alum Bluff form. The concentric sculpture 

is finer and sharper and appears at an earlier stage in 

the growth of the shell.

The characters of the hinge as well as of the pallial 

sinus ally this species with Moerella rather than with 

Tellina s. s.

Occurrence: Chipola formation, localities 10609% 

7893 r, 2213P, 3419 r.

Tellina (Moerella) hypolispa Dall

Plate XXX, Figure 3

1900. Tellina (Merisca) hypolispa Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 1022, pi. 46, fig. 23.

Dall describes this species as follows:

Shell small, inequivalve, inequilateral, plump, polished, the 

right valve flatter; anterior end longer, rounded, the posterior 

rather roundly pointed; base arcuate, near the posterior end a 

little concave; beaks small, pointed; posterior end obscurely 

rayed, slightly flexed; surface smooth or with incremental lines 

but no radial sculpture; anteriorly near the base are usually a 

few sparse, concentric, elevated threads with irregular but 

wider interspaces; the posterior dorsal area, contrary to the 

usual rule, is smooth and shows no traces of lamellation; hinge 

normal, rather feeble; a narrow impressed lunule; interior 

with some obscure radii; pallial sinus as in Angulus. Longitude 

13.5, altitude 8.5, diameter 5 millimeters.

This species is on the border line between Angulus, Moerella, 

and Merisca. The right valve seems flatter, less arcuate below, 

and higher than the left when considered separately.

Type: U. S. Nat. Mus. No. 114597. 

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.
196 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Tellina Jiypolispa has a peculiarly dull and lusterless 

shell, a character which serves to separate it from 

Tellina cloneta Dall, a species of similar dimensions 

and outline though more elongated transversely. The 

concentric threading is very sharp in both and appears 

abruptly in T. Jiypolispa, though at an earlier stage in 

some individuals than in others, and consistently earlier in T. cloneta Dall. The pallia! sinus is coalescent 

ventrally with the pallial line, and both are very 

obscure.

The Oak Grove individuals referred to this species 

are few in number and all of them are immature. They 

indicate a more strongly convex form with more prominent umbones and a more decided posterior sinus. 

As only the left valve is represented the status can 

not be satisfactorily determined.

The general outline and characters of the hinge of 

T. Jiypolispa seem to ally it to Moerella rather than to 

Merisca.

Occurrence: Chipola formation, localities 2213P, 

2211°, 7183°; Oak Grove sand, locality ?2646r.

Tellina (Moerella) acloneta Dall 

Plate XXX, Figure 4

1900. Tellina (Moerella) acloneta Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1025, pi. 46, fig. 16.

Dall describes this species as follows:

Shell minute, elongate, very inequilateral, moderately inflated; anterior end rounded, posterior end somewhat produced, 

flexed, the right valve showing a shallow sulcus extending from 

the umbo to the base behind the posterior basal angle; surface 

polished, smooth except for incremental lines; hinge normal, 

beaks low, almost pustular; lunule present, slightly impressed; 

pallial sinus rounded, short, reaching two-thirds of the way from 

the posterior to the anterior adductor scar; below mostly 

confluent. Longitude 4.7, altitude 3, diameter 1.5 millimeters.

This form is near T. simpsoni, but is smaller, and when compared with specimens of that species of the same size appears 

more compressed and more elongated.

Type: U. S. Nat. Mus. No. 114665.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

This small and dainty form has no decided characters except, possibly, the "almost pustular" umbones 

and the unusually flexuous shell. Still, there is no 

species with which it is readily confusable.

Occurrence: Chipola formation, locality 2213P.

Tellina (Moerella) acosmita Dall 

Plate XXIX, Figure 17

1900. Tellina (Angulus) acosmita Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1026, pi. 46, fig. 1.

Dall describes this species as follows:

Shell small, thin, elongate, inequilateral, rounded in front, 

produced and pointed behind; beaks small, pointed, low; 

disk with usually an obscure constriction mesially; surface 

polished, concentrically feebly striated, near the margins with

regularly spaced concentric grooving; on the posterior dorsal 

slope fine, close, low imbrications; hinge delicate, normal; 

interior thickened ray anteriorly not prominent, touched by 

the anterior end of the high pallial sinus, which is wholly confluent below. Longitude 10.5, altitude 5, diameter 2.5 millimeters.

The most common of the Chipola Tellinidae. The young 

are proportionately longer and perceptibly flexed and rostrate 

behind, characters which lose their prominence in the adults. 

From the following species [Tellina (Angulus) agria Dall] this 

is distinguished especially by its rather sparse concentric sculpture, giving the effect of T. alternata Say in miniature.

Type: U. S. Nat. Mus. No. 114668.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

Tellina acosmita is a thinner, more delicate, and 

more lustrous shell than T. acdlypta, of the Oak 

Grove. In fact, it bears much the same relation to 

T. acalypta as T. cloneta bears to T. Jiypolispa.

Occurrence: Chipola formation, localities 7257P, 

2213C , 2564P, 3419P, 7151°.

Tellina (Moerella) agria Dall 

Plate XXX, Figure 5

1900. Tellina (Angulus) agria Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1027, pi. 46, fig. 11.

Dall describes this species as follows:

Shell resembling the preceding species [Tellina (Angulus) 

acosmita Dall], but more slender and evenly covered with closeset regular concentric threading; beaks small, the minute protoconch distinct, giving a pustular effect; hinge normal, interior normal, the thickened ray present but ill defined, the pallial 

sinus as in T. acosmita. Longitude 6.7, altitude 3.5, diameter 

2 millimeters.

By its fine close striation this species recalls the recent T. 

sybaritica Dall, which is a larger, more solid, and much more 

flexuous shell.

Type: U. S. Nat. Mus. No. 135896.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Shell very small, thin, inequivalve, strongly inequilateral, the anterior portion of the shell produced and 

broadly rounded, the posterior portion much shorter, 

sharply rostrate, obtusely truncate at its extremity. Depression in front of the rostrum broad and 

shallow in the right valve, scarcely perceptible in 

the left; a second very obscure rostral ray developed upon the posterior area and terminating at the 

dorsal extremity of the posterior truncation. A 

smooth sublinear area developed both in front of and 

behind the inconspicuous umbones. Concentric 

threading less crowded but much sharper behind the 

rostrum than upon the medial and anterior portions 

of the shell. Ligament area short and sublinear, opisthodetic. Anterior cardinal of right valve short and 

laminar; posterior short, with a distal sulcus so shallow that the tooth appears simple in weathered specimens. Left valve with a bifid anterior and a laminar
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 197

posterior cardinal. Lateral sockets of right valve 

deep to receive the dentate processes developed upon 

the dorsal margins of the left. Characters of interior obscure. Shell reinforced in adults on the inner 

margin of the adductor scars. Dorsal margin of pallial sinus arching across to the anterior thickened 

ray; ventral margin of sinus confluent with the pallial line.

Tellina ctenota, from the Chipola formation at Alum 

Bluff, is heavier and relatively shorter, with a less 

regular concentric threading.

Occurrence: Oak Grove sand, localities 2646P, 

7054r.

Tellina (Moerella) ctenota Gardner, n. sp.

Plate XXX, Figure 6

Shell small, rather thin, inequivalve, strongly inequilateral, produced and broadly rounded in front, 

short and rather sharply rostrate behind; right valve 

less compressed and more flexuous than the left. 

Umbones small, not conspicuous, with a slight posterior inclination. Lunule sublinear. Escutcheon not 

defined. Posterior keel obtusely angulated, emphasized in the right valve by the broad and shallow 

depression in front of it. Entire external surface 

very finely, closely, and regularly laminated. Ligament short, opisthodetic. Hinge normal, very delicate, a simple anterior and bifid posterior cardinal in 

the right valve and a bifid anterior and simple posterior cardinal in the left; anterior right lateral laminar, 

produced almost to the tip of the umbone; posterior 

lateral much shorter and more remote; dorsal margins of left valve slightly modified to function as 

laterals. Interior feebly rayed, the anterior ray of 

the right valve the stronger. Muscle scars rather 

large, irregular in outline. Pallial scar-very obscure, 

large, and entirely coalescent ventrally.

Dimensions: Right valve (type), altitude, 5.2 millimeters; latitude, 9 millimeters; semidiameter, 1.5 millimeters. Left valve (topotype), altitude, 4.5 millimeters; latitude, 8.5 millimeters; semidiameter, 1.4 

millimeters.

Type: U. S. Nat. Mus. No. 353916.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

Tellina ctenota n. sp. is the close analog of T. acalypta 

Dall in the Oak Grove fauna and of T. piesa in the 

Shoal River. It runs a little smaller, higher, and 

heavier than either of the other two and differs from 

both in the character of the close, sharp, concentric 

lamination which covers the entire shell.

Tellina ctenota has been recognized only at the type 

locality.

Occurrence: Chipola formation, locality 2211 P.

867196 O 50 3 (142-E)

Tellina (Moerella) acalypta Dall 

Plate XXX, Figure 7

1900. Tellina (Angulus) acalypta Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1027, pi. 47, fig. 12.

Dall describes this species as follows:

Shell small, polished, slightly inequivalve, inequilateral; 

anterior end longer, rounded, posterior end produced, attenuated, obliquely truncate, obtusely pointed; beaks small, low, 

the disk near them smooth, polished; surface of the valve 

toward the margins with fine, regular, rather distant concentric 

grooves, the posterior dorsal area with fine concentric wrinkles 

or smooth, the shell showing traces of darker and lighter zones 

and obscure slightly depressed rays; valves moderately convex, the right slightly less so than the left; hinge normal, 

extremely fine and delicate; interior polished, thickened ray in 

left valve present but feeble; pallial sinus high, long, reaching 

the ray, and wholly confluent below. Longitude 10.5, latitude 

5.5, diameter 2.5 millimeters.

This form is not unlike T. poUta Say but is a constantly less 

elevated shell.

Type: U. S. Nat. Mus. No. 135894.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Among the Oak- Grove Tellinas this species is 

second only to T. roburina in abundance. In outline 

and surface characters it is similar to the young of the 

larger roburina, with which it is so commonly associated, but the valves are more highly convex, the 

sculpture upon the dorsal area is finer though equally 

irregular, and the ligament area is more reduced.

The species is restricted in its known distribution 

to the Oak Grove sand, though the analogs in the 

Chipola and Shoal River faunas are very close. T. 

ctenota, of the Chipola, is uniformly sculptured, with 

a very fine, close lamination; T. piesa, which is widely 

distributed in the Shoal River, is consistently more 

compressed.

Occurrence: Oak Grove sand, localities 2646C, 

5632 r, 5631 r, 5633 r, 9961 r.

Tellina (Moerella) piesa Gardner, n. sp. 

Plate XXX, Figures 8-10

Shell small, thin, transversely elongated in outline, 

inequivalve; right valve more strongly compressed 

than the left, strongly inequilateral, much produced 

and broadly rounded anteriorly, very short and obtusely rostrate posteriorly. Umbones very small and 

inconspicuous, posteriorly inclined. Lunule sublinear. 

Escutcheon not developed. Posterior keel obtusely 

angulated, the area behind it obliquely flattened. 

External surface smooth except for a very fine, close 

concentric lamination usually restricted to the posterior area and the ventral portion of the adults; a 

concentric color banding also exhibited in the majority 

of forms, which probably bears a direct relation to the
198 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

original color pattern. Ligament very short, opisthodetic, mounted on short and slender nymphs. Hinge 

normal, very delicate; a simple anterior and bifid 

posterior cardinal in the right valve and a bifid anterior and simple posterior cardinal in the left; laterals 

set very close to the umbones; anterior lateral of right 

valve laminar, produced almost to the apex of the 

umbones; posterior lateral very short and more remote; 

anterior dorsal margin of left valve and to a slight 

degree, the posterior dorsal margin modified to function as laterals. Interior not reinforced except for a 

feeble anterior ray. Adductor scars rather large, irregular in outline. Pallial scars obscure. Pallial sinus 

produced almost but not quite to the posterior adductor 

scar, coalescent ventrally with the pallial line.

Dimensions: Left valve (type), altitude 5.2 millimeters; latitude, 9.5 millimeters; semidiameter, 1.5 

millimeters. Double valves of figured specimen, altitude, 6.7 millimeters; latitude 11 millimeters; diameter, 3 millimeters. The double valves were broken 

after figuring, so that the single valve remains as the 

unique type.

Type: U. S. Nat. Mus. No. 353917. Figured specimen: U. S. Nat. Mus. No. 353918.

Type locality: No. 3742 (type), Shell Bluff, Shoal 

River, Walton County, Fla. No. 3856 (figured specimen), 6 miles west-northwest of Mossyhead, Walton 

County, Fla.

The differences which separate TeUina piesa from 

Tellina acalypta Dall, of the Oak Grove fauna, are 

slight but constant. The Shoal River species is persistently more compressed, with little or no suggestion 

of a second posterior ray. The absence of a uniformly 

developed concentric lamination will serve to separate 

T. piesa from the Chipola analog T. ctenoid Gardner, 

n. sp. The specimens collected 3^2 miles southwest 

of De Funiak Springs are relatively very large and 

exhibit a microscopically fine concentric striation 

toward the umbones, which usually evanesces, however, a little in front of the posterior keel.

Occurrence: Shoal River formation, localities 3856 P , 

3732 r, 3742 P , 1065S r, 5079°, 1066P, 3733 r, 7261 r, 7264 P, 

5192 r, 9960r, 9957 r, 10603 P , ?5618 r.

Genus STRIGILLA Turton

1822. Strigilla Turton, Conchylia insularum britannicarum, 

Dithyra, p. 117.

Type: Tellina carnaria Linnaeus. (Recent on the 

east coast from Hatteras, N. C., to Brazil.)

Shell moderately convex, suborbicular; external 

sculpture oblique over a whole or a part of the valve; 

hinge of right valve armed with two discrepant 

cardinals, of which the posterior is the larger and 

usually bifid, and with two lateral teeth; hinge of 

left valve with two cardinals and two feeble laterals;

pallial sinus varying widely within the limits of the 

genus.

Dall, 7 in 1900, described this genus as follows:

This genus is remarkably characteristic and is found with 

its full development as early as the Oligocene. It is divisible 

into three groups, one typified by S. carnaria, in which the 

pallial sinus is discrepant in the two valves above and wholly 

coalescent below, the upper line uniting the adductors, the 

external chiseled sculpture covering the whole shell; a second 

in which the external sculpture is similar to the preceding but 

the pallial sinus is alike in the two valves and falls short of 

uniting the adductor scars; lastly, a third in which the adductors 

are connected by the pallial line in one valve and the sinus 

falls short in the opposite valve, externally the oblique sculpture 

covers part of the shell, while over the rest it is absent or the 

sculpture is purely concentric, the boundary between the two 

areas being sharply defined by a radial line; these may be 

regarded as sections, viz:

1. Strigilla s. s. Type S. carnaria Linne".

2. Bombergia Dall. Type S. rombergi Morch.

3. Aeretica Dall. Type S. senegalensis Hanley.

The fossils so far as yet known belong to the typical section. 

The oblique external sculpture, which is the most marked 

characteristic of this genus, is in the commoner forms convexly 

waved near the anterior third of the disk, and this region often 

has the sculpture obsolete or even absent in individual specimens; 

the posterior dorsal slope usually has the sculpture in chevron, 

the lines sometimes more or less broken up, and the sculpture 

of this part of the shell, as any one may convince himself by 

examining large series of specimens, has not the constancy in 

pattern of that on the disk of the shell, and therefore should 

not be used as a specific character within narrow limits.

The genus has a rather meager representation in 

the Tertiary and in the warm waters of the Recent 

seas.

Strigilla has a decidedly local distribution in the 

Alum Bluff group. All of the three species determined 

are common within a very restricted area but have 

not been recognized elsewhere. Strigilla georgiana 

is known only from Decatur County, Ga., S. paraflexuosa from the lower bed at Alum Bluff and Sopchoppy, and 8. spJiaerion from the type locality in 

the Shoal River formation of Walton County. S. 

georgiana and S. parafiexuosa are closely allied to 

S. eutykta Gardner and Aldrich from the Miocene 

and Pliocene of the middle Atlantic Coastal Plain and 

to 8,jtexuosa of the Recent fauna, but S. spJiaerion 

has no very near relatives in the described fauna of 

the east coast.

Valves more or less compressed in adult:

Latitude of adult usually exceeding 10 millimeters; umbones 

decidedly anterior in position.

Strigilla georgiana Gardner, n. sp.

Latitude of adult rarely exceeding 10 millimeters; umbones 

subcentral in position.

Strigilla paraflexuosa Gardner, n. sp. 

Valves strongly inflated in adult.

Strigilla sphaerion Gardner n. sp.

i Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 1038,1900.
TELLINACEA, SOLENACEA, MACTEACEA, MYACEA, MOLLUSCOIDEA 199

Strigilla georgiana Gardner, n. sp. 

Plate XXX, Figures 12-13

Shell moderately large for the group, thin, compressed, somewhat obliquely ovate in outline, obtusely 

rostrate posteriorly. Umbones low and inconspicuous, 

the tips minute and orthogyrate, set a little in advance 

of the median line. Anterior dorsal margin very 

gently sloping. Posterior dorsal margin a little steeper. 

Anterior extremity very broadly rounded or obscurely 

truncate. Posterior extremity compressed, obliquely 

produced, and truncated. Base line feebly arcuate, 

more strongly upcurved in front than behind. Lunule 

and escutcheon linear in the right valve, slightly wider 

in the left. External sculpture very fine, the lamellae 

running about 6 to the millimeter, the dorsal edges free, 

slightly flexuous anteriorly but not arched; posterior 

area very finely zigzagged, the chiseling obscure, as a 

rule, directly behind the rostrum, stronger toward the 

margin of the escutcheon. Ligament external, opisthodetic, mounted on a slender nymph, the groove 

extending more than half the length of the escutcheon. 

Dentition delicate; the anterior cardinal of the right 

valve and the posterior cardinal of the left short, 

simple, and laminar; the posterior cardinal of the 

right valve and the anterior cardinal of the left short, 

slender, bifid; modified dorsal margins of right valve 

received in the lateral sockets of the left. Characters 

of interior obscure. Adductor scars rudely circular, 

placed rather low. Pallial sinus observed only in the 

left valve but probably similar in the right; dorsal 

margin of sinus arching across from the posterior to 

the anterior adductor scar, entirely coalescent ventrally. Pallial line rather close to the margin.

Dimensions: Left valve, altitude, 9.8 millimeters; 

latitude, 11 millimeters; semidiameter, 3 millimeters.

Type: U. S. Nat. Mus. No. 353919.

Type locality: No. 7148, near Bainbridge, Decatur 

County, Ga.

Strigilla georgiana is larger than S. paraflexuosa of 

the Chipola formation, more compressed, more produced posteriorly, and with a distinct sculpfure pattern 

upon the posterior area. These differences will serve 

even more readily to separate it from 8. flexuosa Say 

of the Recent east coast fauna. S. sphaerion of the 

Shoal River formation is decidedly more convex, with 

a much wider lunule and escutcheon, an upcurving of 

the lamellae upon the anterior third, and a different 

detail in the sculpturing of the posterior area.

Occurrence: Oak Grove sand, localities 3386 p , 

3385°, 7148C .

Strigilla paraflexuosa Gardner, n. sp. 

Plate XXX, Figures 14-15

Shell small, thin, moderately compressed, equivalve, 

inequilateral, ovate-trigonal in outline, obtusely rostrate posteriorly. Umbonal area well rounded, the

tips of the umbones minute, orthogyrate, very slightly 

anterior in position. Posterior dorsal slope steeper 

and more produced than the anterior. Anterior extremity very broadly rounded, the posterior narrower, 

obtusely and somewhat obliquely truncate. Basal 

margin feebly arcuate, broadly and smoothly upcurved 

anteriorly. Lunule and escutcheon depressed, very 

narrow, slightly wider in the left valve than in the 

right. External sculpture very fine, the lamellae 

running about 6 to the millimeter, not flexuous anteriorly but sweeping across with a very slight downward curvature from the anterior dorsal margin to the 

posterior basal angle; sculpture upon the posterior 

area uniform in the limited number of individuals 

available for observation and following a rather complicated pattern of asymmetric chevrons which split 

into five unequal rays. Ligament external, opisthodetic, the ligament groove produced more than half 

the length of the escutcheon. Dentition delicate; anterior cardinal of right valve and posterior cardinal of 

left short, simple, laminar; posterior cardinal of right 

valve and anterior cardinal of left short, bifid; lateral 

sockets of right valve moderately deep and close to 

the umbones; dorsal margins of left valve modified 

to function as laterals. Characters of adductor and 

pallial scars too obscure to determine.

Dimensions: Right valve (cotype), altitude, 7.2 

millimeters; latitude, 7.8 millimeters; semidiameter, 

2.2 millimeters. Left valve (cotype), altitude, 6.3 

millimeters; latitude, 7.1 millimeters; semidiameter, 

2 millimeters.

Cotypes: U. S. Nat. Mus. No. 114602.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

Strigilla paraflexuosa is the possible precursor of S. 

-flexuosa Say, of the Recent fauna. The Chipola species runs a little smaller and more compressed than the 

Recent, the lunule and escutcheon are narrower, and 

the teeth, especially the lateral sockets of the right 

valve, are more delicate. The external sculpture of 

the two species is very similar in design, though that of 

the Recent form is a little coarser and differs in the details of the posterior area. S. georgiana is larger than 

the Chipola species, more compressed, more produced 

posteriorly, and with a distinct sculpture pattern upon 

the posterior area. S. sphaerion is very much more 

inflated, with a wider lunule and escutcheon, an upcurving of the lamellae upon the anterior third, and a 

distinct sculpturing posteriorly. The common species 

at Sopchoppy, in Wakulla County, is imperfectly preserved but probably referable to S. paraflexuosa. S. 

pisiformis Lamarck, from the Bowden and Recent 

faunas, has much the same general aspect, though it is 

more oblique.

Occurrence: Chipola formation, localities 221 lr, 

10660r, ?7468C .
200 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Strigilla sphaerion Gardner, n. sp. 

Plate XXX, Figures 16-18

Shell moderately large for the genus, rather heavy, 

globose,. equivalve, slightly inequilateral. Umbones 

inconspicuous, slightly anterior, the tips minute and 

feebly opisthogyrate. Lunule rather small, depressed, 

smooth except for incrementals, very unequal in the 

two valves, very small relatively and subtrigonal in the 

right valve, larger in the left valve, feebly concave and 

with a flangelike projection which fills the angle of the 

right valve formed by the dorsal margin and the margin of the lunule. Escutcheon linear in the right 

valve, decidedly wider in the left. Anterior dorsal 

margin short, scarcely sloping. Posterior margin more 

produced and more oblique. Anterior extremity obtusely truncate. Posterior extremity much shorter 

and more decidedly truncate. Base line feebly arcuate, rounding broadly and smoothly into the anterior 

margin, more abruptly into the posterior. External 

chiseling very fine, the lamellae running 5 or 6 to the 

millimeter, the dorsal edges free, broadly upcurved 

anteriorly, feebly concave toward the posterior keel; 

sculpture of posterior area appearing, in most adults, 

in the form of two smooth rays, one directly behind 

the keel, the other a little less than midway between 

the keel and the margin of the escutcheon, these two 

smooth rays separated by a narrow obliquely sculptured ray; behind the second smooth ray a wider and 

more strongly sculptured area; the lamellae on both 

the sculptured surfaces directed downward and backward from the umbones; sculpture in young and unusually fresh adults persistent across the entire keel, the 

lamellae upcurved but not acutely angulated upon the 

anterior of the two smooth rays, acutely angulated 

upon the posterior, the shorter side of the angle toward the escutcheon. Ligament external, opisthodetic, 

not very long, sunk in a deep groove. Dentition normal; anterior cardinal in right valve and posterior 

cardinal in left short, simple, laminar; the posterior 

cardinal in the left and the anterior in the right stouter 

and bifid; lateral sockets of right valve deep, with 

strong inner margins, elevated and obtusely angulated 

medially; dorsal margins of left valve produced to 

function as laterals. Muscle and pallial scars usually obscure; adductor scars relatively rather large, 

irregular in outline. Pallial line quite close to the 

margin; the pallial sinus very large, not discrepant in the two valves, the dorsal margin of the sinus 

arching across from the posterior to the anterior adductor, the ventral margin entirely coalescent with 

the pallial line.

Dimensions: Eight valve (cotype), altitude, 9.8 

millimeters; latitude, 10.1 millimeters; semidiameter, 

4 millimeters. Left valve (cotype), altitude, 11 

millimeters; latitude, 11.6 millimeters; semidiameter, 

4.5 millimeters.

Cotypes: U. S. Nat. Mus. No. 353920.

Type locality: No. 5079, half a mile below Shell 

Bluff, Shoal River, Walton County, Fla.

Strigilla sphaerion is well characterized by the 

highly inflated valves, the anterior upcurving of the 

lamellae, and the details of the sculpture upon the 

posterior keel.

The species is restricted in its known distribution 

to the type locality.

Occurrence: Shoal River formation, locality 5079C .

Genus METIS H. and A. Adams

1858. Metis H. and A. Adams, Genera of Recent Mollusca, 

vol. 2, p. 399.

Type: TeUina meyeri Dunker. (Recent in the 

East Indies.)

H. and A. Adams described this genus as follows:

Shell suborbicular, compressed, surface of valves sulcate; 

hinder flexuosity submedian. Lateral teeth wanting.

This genus, assigned by many conchologists to subgeneric rank under TeUina, originated in the Tertiary 

and still persists in the waters of the tropical seas.

Only the single species has been recognized in the 

Alum Bluff group, and that has a restricted distribution in the Chipola formation.

Metis chipolana Dall 

Plate XXX, Figure 19

1900. Metis chipolana Dall, Wagner Free Inst. Sci. Trans., vol. 

3, pt. 5, p. 1042, pi. 47, fig. 21.

Dall describes this species as follows:

Shell small for the genus, nearly equilateral, not quite equivalve, the left valve slightly larger, evenly rounded in front, 

pointed and attenuated behind; beaks lorv, lunule and escutcheon deeply impressed, narrow; posterior end markedly flexed, 

with an obvious fold or emargination of the valve just above 

the posterior basal angle; surface finely radially striate, with a 

fine concentric lamellation which is more distinct toward the 

base and over the fold; pallial sinus obliquely ascending, free 

from the pallial line below, as in Arcopagia. Longitude 44, 

altitude 36, diameter 16 millimeters.

This species is smoother and more regular than any of the 

other forms known from America and recalls M. dombeyi of 

the Pacific recent fauna.

Type: U. S. Nat. Mus. No. 114629.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

The occurrence of this rather rare species in the 

beds near Tallahassee is very interesting.

Occurrence: Chipola formation, localities 2213 p, 

2211 r, 10660r, 2302r.

Genus MACOMA Leach

1819. Macoma Leach, in Ross, John, A voyage of discovery 

made under the orders of the Admiralty in His Majesty's ships Isabella and Alexander for the purpose of 

exploring Baffin's Bay and inquiring into the probability of a northwest passage, App. 2, p. Ixii.

1819. Macoma Leach, Jour, physique, vol. 88, p. 465
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 201

Type: Macoma tenera (Leach) = Tellina calcarea 

Gmelin. (Recent in the north Atlantic and Arctic 

Oceans.)

Outline transversely ovate or subtrigonal, strongly 

flexuous, as a rule, posteriorly; external surface 

smooth or feebly sculptured concentrically; two divergent cardinals in each valve; laterals absent; pallial sinus often discrepant in the two valves, varying 

widely within the limits of the genus.

The genus is fairly common from the Miocene on 

and is represented in the recent seas by about 100 

species. Though not restricted to the cooler waters, 

the typical members are characteristic of the higher 

latitudes.

Only three species from the Alum Bluff group have 

been described, though there is at least one other present. Macoma s. s. has not been found in the Chipola 

formation. In the cooler-water faunas of the Oak 

Grove sand and in the Shoal River formation, however, 

it is represented, though not abundantly. Psammacoma, the subgenus which includes most of the 

tropical species, is found in the Chipola and is not 

uncommon in the Shoal River. There is no member 

of the genus that constitutes any considerable factor 

in the bivalve faunas of the Alum Bluff.

Umbones anterior. ________-Macoma paralenis Gardner, n. sp.

Umbones posterior_________________ Macoma (Psammacoma).

Posterior extremity very narrow; concentric sculpture 

behind the rostrum relatively feeble.

Macoma (Psammacoma) marmorea Gardner, n. sp. 

Posterior extremity moderately narrow; concentric sculpture behind the rostrum relatively strong.

Macoma (Psammacoma) torynoides Gardner, n. sp.

Macoma calhounensis Dall

1900. Macoma? calhounensis Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 5, p. 1046, pi. 47, fig. 10.

The type is a left valve of Tellina cloneta Dall and 

is from the type locality of T. cloneta. The associated 

fragments are not determinable.

Macoma paralenis Gardner, n. sp.

Plate XXX, Figures 20-21

1900. Macoma lenis Conrad. Dall, Wagner Free Inst. Sci.

Trans., vol. 3, pt. 5, p. 1047 (part). 

Not Tellina lenis Conrad, 1843.

Shell large, very thin, transversely ovate, moderately inflated anteriorly and medially, produced, compressed, and obtusely rostrated posteriorly. Umbones 

small, inconspicuous, slightly opisthogyrate, set in 

advance of the median line; umbonal angle not far 

from 135°. Anterior dorsal margin shorter and more 

gently sloping than the posterior; anterior extremity 

broadly rounded. Posterior extremity obliquely produced and obtusely truncate. Base line nearly horizontal medially, broadly upcurved anteriorly, obtusely 

angulated posteriorly. Neither lunule nor escutcheon 

developed. Surface sculpture incremental in character, feebly developed toward the umbones, very much 

more decided upon the medial and ventral portions

of the shell and particularly behind the rostrum. 

Ligament external, opisthodetic, mounted on a slender 

nymph, the ligament groove extending about one-third 

the length of the posterior dorsal margin. Dentition 

very delicate; the right anterior and the left posterior 

cardinals short, simple, laminar; the right posterior and 

the left anterior cardinals also very short, slender, 

elevated, medially sulcate; laterals not developed. 

Shell reinforced by two inner rays, the anterior decidedly the stronger, especially near the umbones, 

gradually evanescent near the inner ventral extremity 

of the anterior adductor; posterior ray scarcely discernible near the umbones, least feeble along the inner 

margin of the posterior adductor; entire inner surface 

away from the umbones obscurely rayed and concentrically corrugated. Adductor scars irregular and 

obscure. Pallial sinus in right valve very large, ovate, 

covering more than three-fourths the distance between 

the adductor scars, coalescent ventrally; pallial line 

moderately removed from the base. Inner margins 

slightly thickened.

Dimensions: Right valve, altitude, 26.3 millimeters; 

latitude, 41.5 millimeters; semidiameter, 6 millimeters.

Type: U. S. Nat. Mus. No. 157907.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Macoma paralenis has no close allies among the 

described species from Alum Bluff. There is, however, 

a representative of the group which is fairly common 

at Shell Bluff (locality 3742), on Shoal River in Walton 

County, but which is too poorly preserved to warrant 

description. It runs larger than the Oak Grove individuals but is not so high relatively. The umbones 

are apparently more nearly central and the umbonal 

angle larger than in Macoma paralenis. The anterior 

ray is very strongly marked upon the casts, but the 

posterior ray seems to have been little or not at all 

developed. These forms are the probable precursors 

of the group of Macoma constricta Brugui&re.

Occurrence: Oak Grove sand, locality 2646r.

Subgenus PSAMMACOMA Dall

1900. Psammacoma Dall, U. S. Nat. Mus. Proc., vol. 23, p. 292; 

Wagner Free Inst. Sci. Trans., vol. 3, pt. 5, p. 1045.

Type: TeUina Candida Lamarck = Tellina galathea 

Hanley. (Recent in the Indo-Pacific.) 

Dall gives the following description:

Valves equal, produced anteriorly, bluntly truncate and 

hardly flexed posteriorly, with a smooth surface and inconspicuous periostracum. Tropical waters. Type: Tellina Candida (Lam.) Bertin (-T. galathea Hanley, Reeve).

This group by its elongated Tagelus-like form, its delicate, 

often radially hirsute periostracum, and its habitat in the 

warmer seas, where it replaces the Arctic type of Macoma, 

is easily separable from the latter. The pallial sinus is usually 

about half free instead of wholly coalescent below, as more 

usual in typical Macoma.

Most of the Aliim Bluff Macomas are referable to 

this warm-water group.
202 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Macoma (Psammacoma) tracta Dall

Plate XXXI, Figure 1

1900. Macoma (Psammacoma) tracta Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 1053, pi. 47, fig. 13.

1925. Macoma (Psammacoma) tracta Dall. Woodring, W. P., 

Miocene mollusks from Bowden, Jamaica: Carnegie 

Inst. Washington Pub. 366, p. 176, pi. 24, fig. 19.

The type (U. S. Nat. Mus. No. 135702) is from the 

Bowden beds of Jamaica, and I have been unable to 

find the Chipola individuals referred to this species. 

Macoma marmorea Gardner, n. sp., from the Chipola, 

and Macoma torynoides Gardner, n. sp., from the 

Shoal River, are closely allied but are less elongated 

transversely.

Macoma (Psammacoma) torynoides Gardner, n. sp. 

Plate XXXI, Figures 2-4

Shell small, very thin, moderately inflated, subequivalve, strongly inequilateral, the umbones decidedly 

posterior in position. Outline in front of the beaks 

semicylindrical; the dorsal and ventral margins 

approximately parallel, the extremity broadly rounded. 

Shell short and obtusely rostrate behind the beaks; 

posterior dorsal margin slightly excavated directly 

behind the umbones, quite steeply declining; posterior 

extremity short and obtusely truncate, rounding quite 

sharply into the slightly upcurved base. Umbones 

rather prominent, inflated even to their very tips, which 

are feebly opisthogyrate. Lunule suggested by a flattening of the shell in front of the umbones but not 

defined. Escutcheon absent. Surface sculpture restricted to microscopically fine concentric striations, 

except for the fine and irregular corrugation developed 

behind the rostrum. Ligament external, moderately 

produced. Cardinals two in number in each valve, 

very short and delicate. Adductor scars rather small, 

the anterior irregular in outline, the posterior semielliptical. Pallial sinus of right valve ovate, produced 

over about two-thirds of the intervening distance 

between the adductors, partially coalescent ventrally; 

sinus of left valve very obscure, probably with a less 

arcuate dorsal margin. Interior faintly rayed and 

corrugated in harmony with the growth stages.

Dimensions: Right valve (type), altitude, 6.3 millimeters; latitude, 12.5 millimeters; semidiameter, 1.5 

millimeters. Left valve (paratype), altitude, 5.4 millimeters; latitude, 11.5 millimeters; semidiameter, 1.4 

millimeters.

Type: U. S. Nat. Mus. No. 353923. Paratype: 

U. S. Nat. Mus. No. 353921.

Type locality: Right valve (type), No. 5618, 3}^ 

miles southwest of De Funiak Springs, Walton County, 

Fla. Left valve (paratype), No. 3747, 8 miles south 

of Lake De Funiak, Walton County, Fla.

There are a number of poorly preserved individuals 

from Shell Bluff which have been doubtfully referred

to this species, though they are more than double the 

dimensions of the type. Macoma marmorea, from 

Tenmile Creek, is a close analog, but it is more produced and attenuated behind and more feebly sculptured upon the rostrum.

Occurrence: Shoal River formation, localities 2645r, 

3742P, 1065Sr, 5079r, 3748r, 3747r, 5618r.

Macoma (Psammacoma) marmorea Gardner, n. sp. 

Plate XXXI, Figures 5-6

Shell small, very thin, fragile, glistening white, inequivalve, inequilateral, the right valve apparently 

less inflated than the left; both valves compressed, 

attenuated and obtusely rostrate behind. Umbones 

relatively prominent for the group, well rounded even 

to their tips, feebly opisthogyrate, decidedly posterior. 

Outline in front of the beaks semicylindrical, the dorsal 

and ventral margins nearly parallel, the extremity 

broadly rounded; posterior dorsal margin slightly excavated, the lateral margin short and squarely truncate. Base line nearly horizontal. Posterior keel 

obtuse, persistent from the umbones to the base; a 

secondary keel, defined rather by the sculpture than 

the contour, developed behind the first, extending 

from the umbones to the dorsal angle of the posterior 

truncation. Lunule and escutcheon suggested by the 

flattening of the shell over a narrow area and by the 

evanescence of the concentric striae. External sculpture of conch reduced to faint and microscopically 

fine incremental striae except upon the rostrum, where 

the markings are less feeble and flexuous. Prodissoconch concentrically striated. Ligament external, 

opisthodetic, rather short, mounted on a slender 

nymph. Dentition normal, very delicate; the two 

cardinals in each valve very short, slender, and elevated; anterior cardinal of right valve and posterior 

cardinal of left simple, laminar; posterior cardinal of 

right valve and anterior cardinal of left medially sulcate. Interior faintly rayed and concentrically 

wrinkled, often with a slight thickening along the 

inner surface of the posterior adductor but no defined 

ray of callus. Adductor scars rather small, the anterior irregular in outline, the posterior semielliptical. 

Pallial line and sinus obscure; sinus large, oval, extending about two-thirds of the distance across to the 

inner margin of the anterior adductor, coalescent ventrally over about two-thirds of its extent, probably 

with a more arcuate dorsal margin in the right valve 

than in the left; pallial line rather close to the margin.

Dimensions: Altitude, 6.6 millimeters; latitude, 

14.5 millimeters; semidiameter, 2.2 millimeters.

Type: U. S. Nat. Mus. No. 353922.

Type locality: No. 7257, Sexton's marl bed, Tenmile Creek, Calhoun County, Fla.

Macoma marmorea is the close analog of Macoma 

torynoides, of the Shoal River fauna. It seems to be a 

little more attenuated posteriorly and is less strongly
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 203

sculptured upon the posterior area. Both the Chipola 

and the Shoal River species are relatively higher than 

Macoma tracta, from the Bowden of Jamaica. 

Occurrence: Chipola formation, locality 7257 p .

Family SEMEIIDAE Ball

The family Semelidae is most readily separable from 

the Tellinidae by the presence of an internal resilium. 

Genus 8EMEIE Schumacher

1817. Semele Schumacher, Essai d'un nouveau systeme des 

habitations des vers testaces, p. 165.

Type: Tellina reticulata Spengler = Tellina prqficua 

Pulteney. (Pliocene of South Carolina and Florida 

and living from Virginia to Fernando de Moronha and 

east to Bermuda in less than 50 fathoms.)

Shell oval or suborbicular, slightly inequivalve, 

usually more or less rostrate posteriorly; umbones 

subcentral, low, proximate, prosogyrate; ligament 

short, external; resilium strong, internal; hinge armature consisting of two cardinals and two laterals in 

each valve, the laterals of the right valve usually the 

stronger; adductor impressions large, semielliptical; 

pallial sinus profound.

The genus is represented in the Tertiary formations 

by some 30 species, many of them very attractive, and 

in the recent waters by about 60 species, most of them 

tropical.

Though by no means a conspicuous factor in the 

fauna, Semele is represented in the Alum Bluff by 11 

species, some of them rather common. Most of them 

are obviously related to forms prominent in the later 

Tertiary and Recent faunas. Semele chipolana is apparently an ancestral type of Semele leana Dall and 

Semele perlamellosa Heilprin, of the Caloosahatchee 

Pliocene. The rare Semele smithii, also from the 

Chipola, has no very near relatives among the described Tertiary and Recent species. Seven of the 11 

species Semele mutica Dall, S. stearnsii Dall, S. 

scintillata Dall, and S. sellardsi Gardner, n. sp., from 

the Chipola; S. compacta Dall, from the Oak Grove; 

and S. taracodes Gardner, n. sp., and S. paramutica 

Gardner, n. sp., from the Shoal River are members 

of the group of Semele carinata Conrad, S. subovata 

Say, and S. bella Conrad, so prominent in the later 

Miocene and Pliocene. The subgenus Semelina is 

established in the Chipola by S. striulata Dall and in 

the Oak Grove by S. cytheroidea, both of them closely 

related to the Tertiary and Recent S. nuculoidea Conrad. No trace of the existence of this well-characterized group has yet been detected in the Shoal 

River.

The Chipola, with seven species, shows a greater 

diversity than either of the other two formations, but 

the Shoal River, with two species, is perhaps the best 

represented in number of individuals. The Oak Grove 

has a single not uncommon representative in each of 

two subgenera.

Latitude of adult shell exceeding 7 millimeters; sculpture variable but not sharp, crowded and concentric over the entire 

shell:

Latitude of adult shell usually exceeding 20 millimeters:

Surface sculptured with thin, elevated, concentric

lamellae, uniformly spaced- -Semele chipolana Dall.

Surface smooth except for incrementals and microscopicallj- fine radials________>SemeZe smithii Dall.

Latitude of adult shell rarely exceeding 20 millimeters: 

Latitude of adult shell rarely exceeding 12 millimeters; 

shell thin and transversely elongate:

Umbones sculptured with fine, sharp, elevated 

lamellae, closely and regularly spaced; shell 

away from the umbones sculptured with compressed concentric waves or ridges, fairly uniform over the adult shell--Semele mutica Dall. 

Umbones sculptured with fine, sharp lamellae relatively distant and often irregular; shell away 

from the umbones sculptured with broad, concentric waves, tending to become irregular and 

evanesce anteriorly and medially.

Semele stearnsii Dall.

Umbones sculptured with a fine and crowded 

concentric liration; shell away from the umbones radially threaded, the radial sculpture 

developed over the entire shell or restricted to 

one or both of the lateral margins.

Semele scintillata Dall.

Latitude of adult shell usually exceeding 12 millimeters; shell usually rather heavy and ovatetrigonal:

Adult sculptured with numerous concentric folds 

or lamellae not conspicuously flattened over the 

entire adult shell:

Sculpture of concentric folds often tending to 

evanesce anteriorly but not flattened: 

Juvenile sculpture fine, sharp, laminar, 

close-set, regular, -Semele compactaDalL 

Juvenile sculpture fine, obtuse, relatively 

distant, often irregular.

Semele taracodes Gardner, n. sp. 

Sculpture of concentric lamellae sharply 

elevated posteriorly, more or less flattened 

anteriorly and medially.

Semele paramutica Gardner, n. sp. 

Adult sculptured with numerous concentric lamellae flattened over the entire adult shell.

Semele sellardsi Gardner, n. sp.

Latitude of adult shell not exceeding 7 millimeters; sculpture 

sharp, crowded, concentric:

Outline relatively short and trigonal.

Semele (Semelina) cythereoidea Dall. 

Outline relatively elongated transversely.

Semele (Semelina) striulata Dall.

Section 8EMEIE s. s.

Type: Semele reticulata Spengler = Tellina proficua 

Pulteney. (Pliocene of South Carolina and Florida 

and living from Virginia to Fernando de Noronha and 

east to Bermuda in less than 50 fathoms.)

Dall,8 in 1900, gave the following description:

Shell large, sculpture radial and concentric or oblique, reticulate, or nearly absent; chondrophore elongate, resilium large 

and strong, ligament external, feeble; left valve with feebler

8 Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 5, pp. 985-986, 1900.
204 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

laterals, the posterior cardinal slender; right valve with welldeveloped laterals, cardinals subequal, entire; pallial sinus large, 

rounded, obliquely ascending, free of the pallial line.

Semele chipolana Dall 

Plate XXXI, Figure 7

1900. Semele chipolana Dall, Wagner Free Inst. Sci. Trans.,

vol. 3, pt. 5, p. 986, pi. 37, fig. 3. 

1910. Semele perlamelloides Maury, Bull. Am. Paleontology,

vol. 4, No. 21, p. 37, pi. 9, fig. 8.

Dall, in 1900, described this species as follows:

Shell large, solid, rather inflated, nearly equilateral, slightly 

inequivalve; beaks low, adjacent; anterior end longer, sloping 

above, rounded in front and below into the arcuate base; 

posterior end high, bluntly rounded, subtruncate near the base 

the posterior flexure feeble; escutcheon long and narrow, 

lunule wider, elongate, both chiefly impressed on the dorsal 

edge of the left valve; sculpture of regularly spaced, numerous 

low, sharp, thin concentric lamellae, with wider microscopically 

radially striate interspaces; about fifteen lamellae to the centimeter; hinge and other internal characters normal. Altitude 

46, latitude 54, diameter 21 millimeters.

This fine shell is not unlike the Pliocene S. leana, but the 

sculpture in the latter is coarser and more prominent and the 

valves thinner and flatter.

Type: U. S. Nat. Mus. No. 114630.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

The single broken valve from Oak Grove which has 

been referred to S. chipolana represents a distinct 

though analogous species, differing in the thinner 

shell, wider lunule, and less closely spaced concentric 

lamellae. The later collections have yielded only a 

fragment or two of this unusually interesting form.

Occurrence: Chipola formation, localities 2212P, 

2213r, 2211 r, 7183 r.

Semele smith!! Dall 

Plate XXXI, Figure 8

1900. Semele smithii Dall, Wagner Free Inst. Sci. Trans., 

vol. 3, pt. 5, p. 987, pi. 43, fig. 6.

Dall describes this species as follows:

Shell small, slightly inequilateral, thick, solid, the valves 

moderately convex, with a perceptible posterior fold; beaks 

low, small; lunule and escutcheon narrow; anterior end slightly 

longer, sloping above, rounded in front and on the base; posterior end higher, rounded, scarcely truncate below; sculpture of 

hardly perceptible incremental lines and obscure sparse radial 

striations, imperceptible on some parts of the shell; teeth well 

developed; pallial sinus obliquely ascending, rounded in front, 

and rather shorter than usual. Altitude 19, latitude 23, diameter 7 millimeters.

Fragments of two valves were obtained of this interesting, 

nearly smooth species, which is named in honor of Prof. Eugene 

A. Smith, State geologist of Alabama, whose valuable work on 

the geology of the Southern States is well known.

Type: U. S. Nat. Mus. No. 114657. 

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

Not even a fragment of this interesting species has 

appeared in the later collections. 

Occurrence: Chipola formation, locality 2213r.

Semele mutica Dall

Plate XXXI, Figure 9

1900. Semele mutica Dall, Wagner Free Inst. Sci. Trans., vol. 

3, pt. 5, p. 988, pi. 43, fig. 12.

Dall describes this species as follows:

Shell small, compressed, thin, rather elongate, with small, 

low, pointed beaks; anterior end slightly longer, rounded; posterior end shorter, obscurely folded and subtruncate below; 

sculpture * * * with the waves numerous, compressed, 

elevated into narrow, somewhat irregular lamellae, with wider 

interspaces over the whole, sharper and more crowded near the 

posterior dorsal slope; no radial sculpture. * * *

All these forms show a pretty uniform, minute, concentric 

threading, close and almost microscopic, most evident in the 

interspaces, but covering the whole surface, though often worn 

from the more projecting portions, such as the tops of the 

waves. * * *

The variations of this pretty little shell are much greater 

than in any of the recent species I have seen, but it appears to 

be a precursor of such species as the Miocene S. bella Conrad 

and the Pliocene and recent S. cancellata Orbigny.

Dimensions: Altitude, 6.9 millimeters; latitude, 10 

millimeters; semidiameter, 1.5 millimeters.

Type: U. S. Nat. Mus. No. 155781.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Calhoun County, Fla.

The supports for the external ligament are very 

feeble, but the chondrophore is deep and produced 

posteriorly. The dentition is normal, the anterior 

cardinal of the right valve and the posterior cardinal of the left simple and laminar, the posterior 

cardinal of the right valve and the anterior cardinal of 

the left relatively stout and bifid. The dorsal margins 

of the left valve are strongly modified to function 

as laterals and are received in the deep lateral sockets 

of the right valve. The adductor scars are impressed, 

semielliptical, and placed at the extremities of the 

laterals. The pallial line is obscure, the pallial sinus 

large, ovate, its dorsal margin arching high up under 

the umbones.

SemeL mutica is much less common than the related 

$. stearnsii and S. scintUlata. The differences in the 

ornamentation of the shell show up even in the adolescent stages. The early sculpture of $. mutica is 

very fine, sharp, and regular, somewhat similar to 

that of S. stearnsii but sharper and closer and with 

no trace of the radial ornamentation of S. scintUlata. 

The uniformity of the sculpture characters in the 

early stages of development and the constant differences in the young of the three forms under discussion make their specific separation advisable.

Occurrence: Chipola formation, locality 2213P.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 205

Semele stearnsii Dall 

Plate XXXI, Figure 10

1900. Semele mutica var. stearnsii Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 988, pi. 43, fig. 16.

Dall gives the following description:

Shell small, compressed, thin, rather elongate, with small 

low, pointed beaks; anterior end slightly longer, rounded; 

posterior end shorter, obscurely folded and subtruncate below; 

sculpture * * * with few obscure concentric waves stronger about the middle of the disk; there is no radial sculpture,

and the umbones have a slightly compressed appearance.

* * *

All these forms show a pretty uniform, minute, concentric 

threading, close and almost microscopic, most evident in the 

interspaces, but covering the whole surface, though often worn 

from the more projecting portions, such as the tops of the waves.

Dimensions: Altitude, 8 millimeters; latitude, 11.5 

millimeters; semidiameter, 1.6 millimeters.

Type: U. S. Nat. Mus. No. 114656.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

The prodissoconch is a smooth little knob similar to 

that of Semele mutica Dall, but the differences in the 

two species appear with the development of the sculpture. The concentric lamellae are initiated earlier and 

more abruptly upon $. mutica and are sharper and more 

elevated than those of S. stearnsii Dall. The secondary concentric striation shows up better than in S. 

mutica, though this is due in part to the character 

of the primary sculpture. The character of the 

adult sculpture is much more suggestive of the Astartacea than it is of Semele. The concentric undulations are most prominent toward the posterior keel, 

tending to evanesce anteriorly and becoming narrower 

but relatively more elevated behind the rostrum. 

The characters of the ligament and dentition are 

similar to those of $. mutica a feeble external ligament, a well-defined resilifer, two divergent cardinals, 

and sturdy laterals. There is a decided thickening 

of the shell laterally from the umbones down to the 

adductor scars, which are distinctly impressed. The 

pallial sinus arches high up under the umbones as in 

S. mutica, and the pallial line is rather distant from 

the hinge. In spite of the thickened rays and the 

impressed adductor and pallial scars there is a curiously immature aspect about all of this group.

Occurrence: Chipola formation, localities 10609r,

2213P, 3419P.

Semele scintillata Dall

Plate XXXI, Figure 11

1900. Semele mutica var. scintillata Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 988, pi. 43, fig. 2.

Dall gives the following description:

Shell small, compressed, thin, rather elongate, with small, 

low, pointed beaks; anterior end slightly longer, rounded; 

posterior end shorter, obscurely folded and subtruncate below;

* * * sculpture like either of the preceding [Semele 

mutica Dall and S. stearnsii Dall], to which is added radial

8(171% () 50 A (142-E)

threading visible first toward the ends of the shell, in some 

specimens covering the whole disk with rounded radial threads 

with wider interspaces; in the specimens with the strongest 

sculpture the threads overrun the ridges and even become 

nodulous toward the ends of the shell at the intersections.

* * *

All these forms show a pretty uniform minute concentric 

threading close and almost microscopic, most evident in the 

interspaces but covering the whole surface, though often worn 

from the more projecting portions such as the tops of the waves.

* * *

The variations of this pretty little shell are much greater 

than in any of the recent species I have seen, but it appears to 

be a precursor of such species as the Miocene S. bella Conrad 

and the Pliocene and Recent S. cancellata Orbigny.

Dimensions: Altitude, 6.7 millimeters; latitude, 

9.5 millimeters; semidiameter, 1.6 millimeters.

Type: U. S. Nat. Mus. No. 155782.

Type locality: No. 2213, 1 mile below Baileys Ferry, 

Chipola River, Calhoun County, Fla.

The prodissoconch is smooth and rounded like that 

of S. mutica and S. stearnsii. The adolescent shell is 

very finely and regularly striated concentrically, but it 

does not exhibit the sharp primary lamination that is 

characteristic of the other two forms. The secondary 

striation on the adult is fine but remarkably regular 

and distinct and overrides the radials. The radial sculpture is variable in its development but always more 

prominent laterally than medially and posteriorly than 

anteriorly. In some individuals the radial sculpture is 

restricted to the posterior area, and when developed 

over the entire surface the posterior threads are strong 

and well rounded and separated by interspaces of 

approximately their own width, the anterior radials 

less elevated and more closely spaced, the medial 

radials flattened and separated by linear interspaces. 

The characters of the hinge are similar to those of 

S. mutica and S. stearnsii a feeble external ligament, 

a well-excavated resilifer, two rather delicate divergent 

cardinals, and strong laterals placed rather close to 

the beaks. The interior is thickened laterally from 

the umbones to the adductor scars as in S. stearnsii 

Dall, and the characters of the impressed scars and 

the high, arching pallial sinus are similar to those of the 

other members of the group. Semele scintillata is 

more closely related in both the juvenile and the 

adult characters to S. stearnsii than it is to S. mutica.

A juvenile similarly sculptured but more inflated 

occurs in the Shoal River formation on Whites Creek.

Occurrence: Chipola formation, localities 2213 p,

3419 p.

Semele compacta Dall

Plate XXXI, Figures 12-13

1900. Semele carinata var. compacta Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 988, pi. 36, figs. 23, 26.

Dall gives the following description:

This species is of moderate size, rather compressed, with concentric waves separated by equal or wider interspaces; the 

waves vary from sharp edged to flattened; there is fine concen-
206 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

trie and radial striation, feebler on a marked posterior fold and 

somewhat compressed, well-sculptured beaks. Conrad's Abra 

holmesii was founded on Tuomey and Holmes's figure, but I am 

unable to see any discriminating characters either in specimens 

or figures. The figured specimen in the present work is from 

Oak Grove and is characterized by a somewhat more elongated 

form and more uniform and close-set sculpture, especially over 

the posterior dorsal area. The size of those collected is also 

smaller than that of the full-grown Miocene specimens. It 

may perhaps be separated from the type as a variety compacta.

Type: U. S. Nat, Mus. No. 107378.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Dimensions: Figured type, altitude, 12.2 millimeters; latitude, 16.7 millimeters; semidiameter, 2.7 

millimeters.

Semele carinata Conrad, from the later Miocene, 

reaches an altitude of over 20 millimeters. The two 

species follow much the same range of variation in 

outline, though the umbones are more prominent as a 

rule in S. carinata and the umbonal angle smaller. 

The prodissoconch is smooth, shining, and somewhat 

bulbous. The adolescent shell, though relatively 

higher and less elongated transversely than that of the 

Chipola S. mutica Dall, has a similar sculpture of fine, 

sharp concentric laminae. Away from the umbones 

the sculpture offers a wide range of variation. In 

some individuals the concentric folds are very sharp 

and fairly uniform in character, though flattening 

anteriorly. They are usually discontinuous upon the 

obtuse rostrum and much sharper behind it. In other 

individuals the concentric waves become very low and 

ill defined toward the base and quite obsolete anteriorly, though usually more prominent posteriorly than 

upon the medial portion of the shell. A very fine and 

regular concentric secondary striation similar to that 

of the S. mutica group is developed over the entire 

shell, becoming relatively stronger, however, with the 

weakening of the primary sculpture. The radial 

striation is not visible except upon decorticated surfaces. There is a feeble attachment for the external 

ligament and a well-excavated, posteriorly produced 

chondrophore. The dentition is normal, a simple 

anterior cardinal, and a stouter bifid posterior cardinal 

in the right valve and a bifid anterior and laminar 

posterior cardinal in the left valve. The laterals are 

strong and not far removed from the umbones. The 

shell is reinforced, as in S. mutica, by a lateral thickening in the umbonal region. The adductor scars are 

distinct and impressed dorsally. The pallial sinus is 

also distinct and obliquely ovate in outline. The 

dorsal margin of the sinus, though falling, in part, 

within the dorsal third of the shell, is lower than in 

S. mutica. The ventral margin is entirely free.

The smaller, relatively wider, and more elliptical 

shell and the earlier initiation of the concentric sculpture will serve to separate S. compacta Dall from S. 

carinata Conrad. The larger, relatively higher, and

less elliptical shell, particularly in the early growth 

stages, together with the lower dorsal margin of the 

pallial sinus will serve to separate S. compacta from 

the group S. mutica Dall.

Of the two related Shoal River species Semele 

paramutica differs primarily in the adult sculpture, 

Semele taracodes in the juvenile. The adult S. 

paramutica develops, normally, a very regular ornamentation of concentric laminae, usually flattened 

and Tellina-like upon the anterior and medial portions 

of the shell and free and elevated posteriorly. The 

young of S. taracodes are sculptured with fine but 

obtuse lirations, rather distantly spaced and often 

irregular, and are therefore readily separable from 

the young of S. compacta, which have sharp, close, and 

regular threading.

Occurrence: Oak Grove sand, localities 2646C , 

9961 r, 10659P .

Semele taracodes Gardner, n. sp.

Plate XXXI, Figures 14-15

Shell moderately thin and compressed, not very 

large, ovate-trigonal to transversely elongate in 

outline. Prodissoconch minute, smooth, shining, 

and bulbous. Umbones low, flattened, placed a 

little behind the median horizontal. Posterior dorsal 

margin more steeply sloping than the anterior. 

Anterior extremity produced and very broadly 

rounded, posterior obscurely rostrate and obtusely 

truncate. Base line arcuate. External surface sculptured away from the umbones with compressed concentric ridges, often irregular, which tend to evanesce 

anteriorly and are more elevated and more sharply 

pinched posteriorly; a very fine secondary striation 

also developed over the greater part of the shell; 

both primary and secondary sculpture little or not 

at all developed near the umbones, least feeble 

behind the rostrum. External ligament support 

short and light. Chondrophore narrow but deeply 

excavated, posteriorly produced parallel to the posterior dorsal margin. Hinge normal; dentition rather 

concentrated; anterior cardinal of right valve thin, 

laminar, coalescent at its base with the dorsal margin; 

posterior cardinal of right valve and anterior cardinal 

of left rather slender, deltoid, medially sulcate; 

right lateral sockets deep, their inner margins elevated 

medially; dorsal margins of left valve modified to 

function as laterals; interior thickened in the umbonal 

region. Muscle scars distinct, semielliptical in outline, their dorsal margins impressed, set rather high 

at the extremities of the laterals. Pallial line moderately close to the margin; pallial sinus large, somewhat obliquely ovate, covering about three-fourths of 

the distance between the inner margins of the muscle 

scars; dorsal margin of sinus feebly arcuate; lateral 

margin broadly rounded; ventral margin almost 

entirely free from the pallial line.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 207

Dimensions: Right valve, altitude, 12.1 millimeters; 

latitude, 16.5 millimeters; semidiameter, 3 millimeters.

Type: U. S. Nat. Mus. No. 353926.

Type locality: No. 5079, half a mile below Shell 

Bluff, Shoal River, Walton County, Fla.

Semele taracodes is very close in its adult characters 

to S. compacta Dall. The examination of a large 

number of the young of both species makes it certain, however, that the juvenile characters are constantly distinct. In place of the fine, rather close, 

and regular lamination of S. compacta there is 

developed in S. taracodes only an obtuse and irregular 

threading, least feeble posteriorly. The adult sculpture of S. paramutica is closer than that of S. taracodes, sharper, more elevated posteriorly, and flattening rather than evanescing anteriorly.

Occurrence: Shoal River formation, localities 5079 p , 

9957 r, 10603 P .

Semele paramutica Gardner, n. sp. 

Plate XXXI, Figures 16-17; Plate XXXII, Figure 28

Shell rather small, compressed, moderately thin; 

ovate-trigonal in outline. Anterior extremity produced and very broadly rounded. Posterior extremity shorter, obtusely rostrate. Base line arcuate, 

broadly upcurved anteriorly. Umbones low, flattened. Lunule and escutcheon not defined. External surface sculptured with concentric laminae, very 

fine, sharp, and closely spaced upon the umbones, 

flattened and closely overlapping anteriorly and medially in Tellina, increasingly elevated posteriorly and 

less closely spaced behind the rostrum; traces of a 

very faint secondary concentric and radial striation 

sometimes visible posteriorly. External ligament 

groove very shallow. Chondrophore deeply excavated, posteriorly produced. Cardinals rather frail; 

a simple laminar anterior and a mesially sulcate posterior cardinal in the right valve and a sulcate anterior 

and simple posterior cardinal in the left. Lateral 

sockets of right valve deep, their inner margins 

acutely elevated medially; dorsal margins of left 

valve modified to function as laterals. Adductor 

scars distinct but scarcely impressed, rudely semielliptical in outline. Pallial line moderately distant 

from the base, the sinus apparently a little lower and 

smaller in the right valve than in the left, somewhat 

obliquely ovate in both, the dorsal margin feebly or 

not at all arcuate, the ventral margin not coalescent.

Dimensions: Right valve (type), altitude, 10.5 

millimeters; latitude, 14.5 millimeters; semidiameter, 

2.2 millimeters. Left valve (paratype), altitude, 

11.4 millimeters; latitude, 14.5 millimeters; semidiameter, 2.7 millimeters.

Type: Right valve, U. S. Nat. Mus. No. 353924. 

Paratype: Left valve, U. S. Nat. Mus. No. 355925.

Type locality: Right valve (type), No. 3742, Shell 

Bluff, Shoal River, Walton County, Fla. Left valve 

(paratype), No. 3748, Somerville mill race, Walton 

County, Fla.

Semele paramutica is rather widely distributed in 

the Shoal River and seems to be peculiar to it.

This species has a fashion of weathering in broad 

and somewhat irregular concentric waves that give 

to the shell much the aspect of the smaller, thinner 

Semele stearnsii Dall from the Chipola.

The allied Shoal River species S. taracodes has a 

more obtuse, more distant, and less regular juvenile 

sculpture than S. paramutica. The adult sculpture 

of S. taracodes is less crowded and less regular than 

that of S. paramutica.

Semele subovata Say and Semele bella Conrad, of 

the later Miocene, are probable descendants of this 

group.

Semele mutica Dall, from the Chipola, and Semele 

compacta, from the Oak Grove, are analogous species. 

S. mutica is smaller than S. paramutica, more elongated 

transversely, with a concentric sculpture of compressed 

ridges, only a little sharper and more crowded posteriorly than anteriorly. S. compacta is very close to S. 

paramutica in general dimensions and outline, but, as 

in the Chipola S. mutica, the concentric ridges are 

only a little less elevated upon the anterior and medial 

portions of the shell than they are upon the posterior, 

neither the Chipola nor the Oak Grove species exhibiting the Tellina-likG flattening of the crowded concentric laminae upon the anterior and medial portions of 

the shell. The secondary concentric and radial sculpture is much less commonly and more feebly developed 

in S. paramutica than in either S. mutica or S. compacta. The pallia! sinus is smaller in S. paramutica 

than it is in S. mutica, and the dorsal margin does not 

arch so high beneath the umbones.

Occurrence: Shoal River formation, localities 3742 p , 

5184 r, 2238 P , 9958 P , 3748 C , ?5618 r.

Semele sellardsi Gardner, n. sp. 

Plate XXXI, Figures 18-19

Shell rather small and thin, moderately compressed, 

ovate-trigonal in outline. Umbones flattened, not 

very prominent, orthogyrate, set a little behind the 

median vertical. Anterior dorsal margin less steeply 

sloping than the posterior. Anterior end of shell more 

compressed than the posterior and broadly rounded 

laterally. Posterior dorsal margin obliquely descending, the lateral margin arcuate. Base line nearly 

horizontal medially, broadly upcurved laterally. Posterior area obscurely defined by an incipient fold. 

Prodissoconch smooth, shining, somewhat bulbous. 

Conch finely sculptured concentrically over its entire 

surface; earliest sculpture of sharp lirations; the adolescent shell ornamented with laminae less crowded and
208 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

more elevated, posteriorly flattened and closely overlapping anteriorly, the free edges dorsally inclined; 

change from adolescent to adult sculpture abrupt; a 

sculpture of very fine and regular lamellae similar to 

that upon the anterior portion of the adolescent shell 

developed over the entire anterior and medial portions 

of the adult; sculpture reduced directly behind the 

obscure posterior fold to a few irregular incrementals, 

becoming sharp and laminar directly in front of the 

dorsal margin, the lamellae similar to those developed 

upon the adolescent shell and like them ventrally 

inclined. Ligament internal, the chondrophore nar- 

'row but rather deeply excavated, posteriorly produced, 

slightly undercutting the dorsal margin. Dentition 

rather delicate, imperfectly preserved; two cardinals 

in each valve diverging slightly beneath the tips of the 

umbones; the posterior cardinal of the right valve and 

the anterior cardinal of the left stouter and possibly 

bifid; lateral sockets of right valve deep, their inner 

margins elevated medially into a dentate process; the 

dorsal margins of the left valve modified to function 

as laterals. Interior slightly thickened laterally toward 

the umbones. Adductor scars distinct, irregular in 

outline, set rather high. Pallial line moderately distant from the base, the sinus very large, obliquely 

ascending and ovate in outline, its broadly rounded 

extremity rather close to the thickened inner margin of 

the anterior adductor; dorsal margin of sinus feebly 

arcuate, the ventral margin not coalescent.

Dimensions: Altitude, 11 millimeters; latitude, 14.5 

millimeters; semidiameter, 3.3 millimeters.

Type: U. S. Nat. Mus. No. 353927.

Type locality: No. 7893, Boynton Landing, Choctawhatchee River, Washington County, Fla.

Semele sellardsi i§ remarkable among the Alum 

Bluff members of the genus for its high ovate outline 

and the fineness and regularity of the adult sculpture. 

It is doubtless a member of the large group of Semele 

subovata Say, but its closer relations are not obvious.

I have the honor of dedicating this species to its 

collector, Dr. E. H. Sellards, formerly State geologist 

of Florida, now acting director of the Texas Bureau 

of Economic Geology and Technology.

Occurrence: Chipola formation, locality 7893 r.

Subgenus SEMELINA Dall

1900. Semelina Dall, Wagner Free Inst. Sci. Trans., vol. 3, 

pt. 5, p. 986.

Type: Semelina nuculoides Conrad. (Upper Miocene of Virginia and North Carolina; Pliocene (Caloosahatchee) of Florida; Recent from Hatteras to the 

West Indies.)

Dall gives the following description:

Shell small, nuculiform; sculpture uniform, close, concentric; 

chondrophore short; left valve without distinct laterals, the 

dorsal margins fitting above the laterals of the right valve; 

left posterior cardinal absent or obsolete, the anterior cardinal 

bifid; otherwise as in Semele s. s.

The species of this section are very similar to one another 

and have extended from the Oligocene through all the Tertiary 

horizons to the present fauna. For this reason it seems worthy 

of sectional rank. The characters by which the shell differs 

from Semele proper are only such as are usually correlated with 

diminished size.

An exceedingly thin and laminar left posterior 

cardinal is developed in both of the Alum Bluff 

species. In most individuals it is broken, but in a 

few it is preserved entire.

Semele (Semelina) cythereoidea Dall

Plate XXXII, Figures 1-5

1900. Semele cythereoidea Dall, Wagner Free Inst. Sci. Trans., 

vol. 3, pt. 5, p. 994, pi. 44, fig. 5.

Dall describes this species as follows:

This species, which is abundant in the Chipola marl, is much 

like the preceding (Semele nuculoidea Conrad), from which it 

differs by its shorter and more triangular form, like a miniature 

Cytherea, and by its very fine, close, concentric striation. In 

the latter feature it surpasses the Oak Grove S. nuculoidea var. 

striulata, which in its turn is more finely sculptured than the 

Miocene type, but the striulata is not intermediate in form, 

being more elongated and parallel-sided than either its ancestor 

or its descendant, if we may so term the Chipola and Duplin 

species, respectively. The S. cythereoidea is also on the whole a 

smaller species than either of the others mentioned, the largest 

specimens among a large number measuring 5 millimeters long 

by 3.75 high and having a diameter of 1.7 millimeters. These 

differential characters with the figure will serve better to define 

the present species than a more elaborate description, which 

would merely recapitulate for the most part the characters of 

S. nuculoidea.

Type: U. S. Nat. Mus. No. 114678.

Type locality: No. 2564, McClelland farm, 1 mile 

below Baileys Ferry, Calhoun County, Fla.

The slight flattening of the anterior portion of the 

shell in Figure 1 is badly expressed and much exaggerated by the artist. The angular outline of the anterior extremity is due to the broken margin of the shell.

Both Semele striulata and S. cythereoidea vary rather 

widely within their small limits, so that there are a 

large number of peripheral forms which it would be 

exceedingly difficult to separate on outline alone. 

The sculpture of the Chipola species is not so much 

finer than that of the Oak Grove form, but it is relatively more flattened anteriorly and more elevated 

posteriorly. In addition there is developed in most 

of the Chipola forms an exceedingly faint radial striation upon the posterior area. This is also discernible 

on some of the Oak Grove individuals but is usually 

fainter. The characters of the interior are similar in 

the two species, though the shell of S. cythereoidea 

is the thinner, as a rule, and the dentition more delicate. There is a minute subumbonal chondrophore, 

a simple anterior cardinal and a stouter, feebly bifid 

posterior cardinal in the right valve, and a bifid 

anterior and simple laminar posterior cardinal in the 

left valve. The strong, produced lateral sockets of 

the right valve receive the modified dorsal margins
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 209

of the left valve. The adductor scars are obscure, 

the pallial sinus large, ovate, obliquely ascending, not 

coalescent ventrally.

No representative of these small nuculoid forms has 

yet been recognized in the Shoal River formation.

Occurrence: Chipola formation, localities ?10609r, 

?7893r, 2213P, 2564r, 3419r.

Semele (Semelina) striulata Dall 

Plate XXXII, Figures 6-8

1900. Semele nuculoidea var. striulata Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 994.

Dall describes this variety as follows:

The variety striulata Dall, from the uppermost Oligocene of 

Oak Grove, Fla., differs from the typical Miocene phase of this 

species by its finer and, closer striation, and in most of the 

specimens by its more parallel-sided and elongated shell.

Shell very small, moderately heavy, evenly inflated, 

ovate-trigonal to subcylindrical in outline. Umbones 

minute, acutely pointed and opisthogyrate, thrown 

into prominence by the excavation of the dorsal margin 

behind them, placed within the posterior third. Anterior extremity produced, the dorsal and ventral margins rudely parallel, the lateral margin broadly 

rounded. Posterior end short, flattened but not rostrate, feebly concave directly behind the umbones, 

convex toward the base. External surface sculptured 

with a microscopically fine and close concentric lamination, more or less flattened anteriorly and erect 

posteriorly; a microscopically fine and fortuitous radial striation sometimes perceptible upon the posterior 

area. Ligament internal, lodged in a minute, subumbonal chondrophore. Dentition normal; cardinals 

two in number in each valve, the anterior of the right 

valve simple and laminar, the posterior bifid, the posterior cardinal of the left valve bifid, and the anterior 

very thin and simple; lateral sockets of right valve 

remarkably strong for so small a shell, the inner margins elevated into dentate processes; dorsal margins 

of left valve modified to function as laterals. Interior 

often slightly thickened over the area of the attached 

mantle surface; adductor scars distinct, the anterior 

comparatively large and irregular in outline, the posterior subcircular. Pallial line distinct; the sinus very 

large, obliquely ascending, covering perhaps one-third 

of the entire inner surface of the shell, extending 

about three-fourths of the distance across to the anterior adductor and almost as high as it is broad; lateral 

extremity arcuate; ventral margin not confluent with 

the pallial line.

Dimensions: Right valve (cotype), altitude, 3.3 

millimeters; latitude, 4.5 millimeters; semidiameter, 

1.1 millimeters. Left valve (cotype), altitude, 3 millimeters; latitude, 4.2 millimeters; semidiameter, 0.9 

millimeters.

Cotypes: U. S. Nat. Mus. No. 353928.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The Chipola analog S. cytliereoidea Dall is higher 

relatively and more finely and sharply sculptured.

Occurrence: Oak Grove sand, localities 2646P, 

5632r, 7054r, 9961 r.

Genus ABRA (Leach MS.) Lamarck

1818. Abra (Leach MS.) Lamarck, Histoire naturelle des 

animaux sans vertebres, vol. 5, p. 492.

Type: Mactra tennis Montagu. (Recent off the 

English and Irish coasts.)

Most of the European conchologists, including 

Forbes and Hanley, Stoliczka, and Lamy, reject 

Abra in favor of Syndesmya Recluz, 1843. Lamarck, 

in listing Leach's manuscript name, did not, to be 

sure, characterize the genus, but he gave a new name 

to a known and recognizable shell, and as Cossmann9 

pointed out, the genotype is beyond question. Whether 

or not Lamarck had it in his mind to create a new 

genus is not the concern of nomenclature.

Shell small, ovate to trigonal or rudely quadrate in 

outline; rather compressed, flexuous posteriorly. 

Umbones low, subcentral to posterior, prosogyrate. 

Outer surface smooth or finely sculptured concentrically. Internal ligament stronger than the external, 

the chondrophore narrow but produced and deeply 

inset beneath the umbones. Dentition delicate; normally two simple cardinals developed in each valve; 

the modified dorsal margins of the left valve received 

in the lateral sockets of the right. Pallial sinus deep, 

confluent ventrally with the pallial line.

The Recent forms are relatively few in number but 

have a wide geographic and bathymetric range.

Two species have been recognized in the Alum Bluff 

group Abra cylidon Gardner, n. sp., from the Shoal 

River formation, known only from a single valve, and 

the rather common Chipola species Abra lapocJii Gardner, n. sp., a form curiously close in its external aspect 

to a coexistent Tellina.

External surface smooth.._______^4.&ra cylidon Gardner, n. sp.

External surface concentrically laminated away from the 

umbones-________-___-___-___^4.&ra lapochi Gardner, n. sp.

Abra cylicion Gardner, n. sp.

Plate XXXII, Figures 9-10

Shell small, thin, flexuous, strongly convex anteriorly, less strongly posteriorly, ovate-trigonal in outline. 

Umbones small but well rounded, feebly prosogyrate, 

placed a little behind the median horizontal. Neither 

lunule nor escutcheon defined. Anterior extremity 

produced and very broadly rounded. Posterior extremity shorter and obtusely rostrate. Anterior 

dorsal margin more gently sloping than the posterior. 

Anterior lateral margin broadly and smoothly rounded;

9 Cossmann, A. E. M., and Peyrot, A., Conchologie nSogfinique de I'Aquitaine, 

vol. 1, p. 215, 1910.
210 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

posterior lateral margin quite squarely truncate. 

Base line flexuous, down-curved anteriorly along the 

area of the maximum convexity. External surface 

smooth excepting for faint incremental striae, least 

feeble behind the rostrum. A strong color banding 

preserved, possibly inherited from the original pattern. 

External ligament support very frail, the groove behind 

it shallow. Chondrophore narrow but deep, posteriorly produced and undercutting the posterior dorsal 

margin. Right cardinals delicate, the anterior simple, 

laminar, free from the dorsal margin, the posterior 

also slender but mesially sulcate. Lateral sockets 

very shallow and distant from the umbones. Interior 

feebly corrugated, the adductor and pallial scars 

moderately distinct for so thin a shell. Muscle scars 

not very large, rudely semielliptical in outline, placed 

at the extremities of the lateral sockets. Pallial sinus 

large, produced, about three-fourths of the distance 

across to the anterior adductor; the dorsal margin of the 

sinus nearly horizontal and falling only a little above 

the median line of the shell, its lateral extremity rather 

narrowly rounded, obliquely descending to the pallial 

line, which falls rather close to the basal margin.

Dimensions: Altitude, 7.5 millimeters; latitude, 10 

millimeters; semidiameter, 2.8 millimeters.

Type: U. S. Nat. Mus. No. 353929.

Type locality: No. 3856, 6 miles west-northwest of 

Mossyhead, Walton County, Fla.

The inflated, almost cup-shaped outline and the 

absence of external sculpture will readily separate the 

Shoal River form from Abra lapocJii, of the Chipola. 

Abra triangulata Dall, from the Bowden, is more 

closety allied, but the shell is smaller and thinner and 

the laterals even more reduced than in A. cylicion.

Occurrence: Shoal River formation, localities, 

3S56r, 7264r.

Abra lapochi Gardner, n. sp.

Plate XXXII, Figures 11-13

Shell small, rather thin, strongly inflated, inequivalve, inequilateral, transversely ovate-trigonal in 

outline. Umbones well rounded, acute at their tips, 

feebly prosogyrate, posterior in position. Lunule 

rather short, lanceolate, depressed, outlined by a narrow keel, wider in the right valve than in the left. 

Escutcheon linear in the right valve, perceptibly 

wider in the left, extending the entire length of the 

posterior dorsal margin. Anterior extremity of shell 

produced and broadly rounded; the anterior dorsal 

margin rudely parallel with the base; the anterior 

lateral margin smoothly rounded. Posterior extremity short and flexuous, obliquely truncate. Right 

valve obtusely rostrate, the rostrum emphasized by 

the rather sharp constriction behind it. Left valve 

with an obscure fold corresponding to the depression

in the right valve and a very shallow depression corresponding to the keel in the right valve, with a second 

narrow and obscure fold directly behind the escutcheon. Basal margin flexuous, sharply produced at the 

posterior basal angle. External surface polished, 

smooth toward the umbones except for feeble incrementals, sculptured on the medial and ventral portions 

with fine, sharp, closely and regularly spaced concentric laminae inclined to be somewhat flattened 

anteriorly and medially and more nearly erect upon 

the rostrum, particularly of the left valve. External 

ligament attached to a short and frail support with a 

narrow groove behind it. Resilifer narrow but 

rather deep, posteriorly produced parallel to the 

dorsal margin. Cardinals two in number in each 

valve; the right anterior and the left posterior simple 

and laminar; the left anterior and the right posterior 

slender and deltoid but not mesially sulcate; lateral 

sockets in right valve fairly close to the umbones, 

fairly deep, with strong, medially elevated inner 

margins; dorsal margins of left valve modified to 

function as laterals. Adductor and pallial scars often 

obscure; adductor scars rather large, irregular in 

outline. Pallial sinus apparently similar in the two 

valves, the dorsal margin rising a little after quitting 

the upper inner margin of the posterior adductor, then 

gently descending and near the anterior adductor 

scar rounding rather sharply into the pallial line; 

ventral margin entirely coalescent with the pallial 

line; pallial line running nearer to the base posteriorly 

than anteriorly.

Dimensions: Right valve (cotype), altitude, 6.7 

millimeters; latitude, 9.5 millimeters; semidiameter,

2.5 millimeters. Left valve (cotype), altitude, 6.9 

millimeters; latitude, 10.5 millimeters; semidiameter,

2.6 millimeters.

Cotypes: U. S. Nat. Mus. No. 353930.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

Abra lapochi is readily separated from Abra cylicion, 

the only other representative of the genus in the Alum 

Bluff group, by the more transversely elongate, less 

inflated valves and the development of a surface 

sculpture. There is, however, an extraordinarily 

close superficial resemblance between Abra lapochi 

and the coexistent Tellina Tiypolispa Dall. The general dimensions and contour of the two species are 

the same, though the Abra is a little more inflated, 

and there is a remarkable resemblance in the surface 

polish and sculpture. In fact, if the characters of 

the interior were not known it would be a matter of 

no little difficulty to discriminate between the two 

forms.

Occurrence: Chipola formation, localities 2213r, 

2211 C .
TELLINACEA, SOLENACEA, MACTRACEA, MY ACE A, MOLLUSCOIDEA 211

Family DONACIDAE Deshayes 

Genus DONAX (Linnaeus) Lamarck

1758. Donax Linnaeus, Systema naturae, 10th ed., p. 682.

(No type selected.) 

1799. Donax Lamarck, Prodrome d'une nouvelle classification

des coquilles: Soc. hist. nat. Paris Mem., p. 85. 

1847. Donax Gray, Zool. Soc. London Proc., vol. 15, p. 187.

Type: Donax rugosa Linnaeus. (Recent in the 

West Indies.)

Shell rather solid, moderately inflated, of varying 

dimensions, elongate cuneate to trigonal to subcylindrical in outline. Umbones subcentral to posterior, 

opisthogyrate. Sculpture finely radial, often subcutaneous, sometimes punctate. Ligament both external and internal; external ligament short, heavy, inset; the resilium seated on short, usually excavated 

nymphs. Dentition rather rude; normally two cardinals in each valve, one of them commonly bifid; 

laterals varying widely in strength and relative position within the genus. Pallial sinus deep, partly confluent ventrally with the pallial line. Inner margins 

serrate.

The genus is remarkably uniform and well characterized by its solid, more or less pronounced cuneate and flexuous valves, opisthogyrate and usually 

posterior umbones, and serrated inner margins. The 

earliest known occurrence of the form is in the Eocene. 

The living species, about 100 in number, inhabit the 

sandy beaches of the warm and tropical seas. They 

are lovely little bivalves, ornamented with varicolored rays upon a dull gray or dun background. The 

"pampalone shells," as they are called along the Florida coast, where they are particularly abundant, are 

used to a considerable extent for food.

Considering that the genus was fairly well established in the early Miocene and that the Alum Bluff 

was laid down under warm temperate to subtropical 

conditions, Donax has a surprisingly meager representation. Five species and subspecies have been described, and there is at least one other indicated only 

by fragments, but all of these are comparatively rare. 

The three Chipola forms are closely related, but they 

are quite distinct from either the Oak Grove or the 

Shoal River species. The Oak Grove D. aldrichi is 

without close allies, but the Shoal River D. valhosierr is 

probably referable to the group of D.fossor Say and 

D. emmonsi Dall, of the later Miocene and Pliocene, 

and D. variabilis Say, of the Recent fauna.

Umbones conspicuously posterior; the anterior extremity very 

much narrower and more produced than the posterior; posterior area not concentrically laminated:

Shell only a little more than half as wid° as it is high, not 

flexuous nor constricted behind the anterior rostrum.

Donax chipolanus Dall s. 1.

Shell compressed anteriorly, not rostrate; posterior 

dorsal margin short, rectilinear.

Donax chipolanus Dall s. s.

Shell obtusely rostrate anteriorly; posterior dorsal 

margin scarcely perceptible, merging with the lateral 

margin.

Donax chipolanus subsp.? curtulus Dall. 

Shell decidedly more than half as wide as it is high, flexuous, constricted behind the anterior rostrum.

Donax trueloides Gardner, n. sp.

Anterior dorsal margin subparallel to the base; posterior area 

concentrically laminated.

Donax (Paradonax) aldrichi (Dall MS.), Gardner. 

Umbones not conspicuously posterior; the anterior extremity 

only a little narrower and more produced than the posterior; 

posterior area not concentrically laminated.

Donax (Paradonax) valhosierr Gardner, n. sp.

Section DONAX s. s.

Type: Donax rugosa Linnaeus. (Recent in the 

West Indies.)

Donax s. s. includes the elongate cuneate forms with 

the radial sculpture relatively well developed, the posterior of the two right cardinals heavy and often bifid, 

the laterals usually close to the beaks and fairly strong. 

The group is abundantly represented in the West 

Indies and has a wide distribution in the warm waters 

of the Atlantic and Pacific Oceans.

Donax chipolanus Dall

Plate XXXII, Figure 18

1900. Donax chipolana Dall, Wagner Free Inst. Sci. Trans., vol. 

3, pt. 5, p. 966, pi. 44, fig. 20.

Dall describes this species as follows:

Shell small, thin, smooth, with faint radial striation behind; 

anterior end smaller, produced, rather bluntly rounded at the 

end; anterior dorsal margin rectilinear, basal margin nearly 

straight; posterior end wider, short, not carinate or markedly 

truncate but bluntly rounded; right valve with well-marked 

sockets for the laterals, the anterior one longer; ventral edge 

finely serrate, the serrations shorter below the beak; pallial 

sinus subquadrate, horizontal, ventral portion largely confluent 

with the pallial line. Longitude 9.5, altitude 5.5, diameter 3 

millimeters.

A single valve was obtained by Burns, which has been bored 

by a gastropod. The shell is remarkably fresh and still retains 

traces of purple coloration along the hinge line.

Type: U. S. Nat. Mus. No. 114682.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

The type remains unique.

The short, wide posterior end and the produced and 

tapering anterior end readily separate the species from 

the larger, heavier, trigonal D. trueloides, the relatively 

lower D. aldrichi, and the less strongly inequilateral 

D. valhosierr.

Occurrence: Chipola formation, locality, 2213r .

Donax chipolanus subsp.? curtulus Dall

Plate XXXII, Figure 19

1900. Donax chipolana subsp. curtula Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 5, p. 966.

Dall gives the following description:

With it [Donax chipolana Dall] was another valve of smaller 

size which may represent a distinct species or an extreme varia-
212 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

tion of the preceding. The umbo is more posterior, the anterior end more pointed, and the posterior end shorter and more 

rounded. In view of the variability of species of this group I 

prefer, until more material comes to hand, to regard it as a 

variety curtula of the D. chipolana.

Dimensions: Altitude, 3.5 millimeters; latitude, 5.5 

millimeters.

Type: U. S. Nat. Mus. No. 108446.

Type locality: No. 2213, 1 mile below Baileys Ferry, 

Chipola River, Calhoun County, Fla.

No further material has been obtained to aid in 

establishing the status of this single valve. The shell 

is worn but seems to be heavier than that of D. 

chipolanus and is decidedly more convex, especially 

toward the umbones. The dentition of the inner 

margins is stronger in the smaller shell, though the 

relative strength of the anterior and posterior series 

is much the same. On the other hand, there is a 

remarkable similarity in the general contour of these 

two unusual shells. Further evidence is needed before 

a satisfactory decision can be made.

Occurrence: Chipola formation, locality 2213r.

Donax trueloides Gardner, n. sp.

Plate XXXII, Figures 20-22

Shell of moderate dimensions, polished, rather 

heavy, flexuous, high, trigonal hi outline, quite strongly 

inflated posteriorly, rather compressed anteriorly, 

obscurely rostrate posteriorly, rather sharply rostrate 

anteriorly and constricted behind the rostrum. Umbones prominent, somewhat angular, flattened upon 

their summits, the tips acute, incurved, and opisthogyrate. Lunule and escutcheon suggested by a slight 

change in the surface texture and the absence of any 

radial lineation. Anterior extremity obliquely truncate from the umbones to the anterior basal margin, 

obtusely angulated ventrally. Posterior dorsal margin 

projecting slightly behind the umbones, then rounding 

sharply into the lateral margin. Posterior lateral 

margin steeply descending, very feebly arcuate, merging rather smoothly into the base. Base line flexuous, 

produced at the anterior rostral angle, constricted 

behind it, and broadly curved posteriorly. External 

surface faintly lineated radially, the radials least 

feeble over a cordate area behind the posterior rostrum; a fine lineation also discernible in front of the 

posterior rostrum and behind the anterior, absent altogether directly behind the anterior margin and over 

a cordate area behind the umbones. Ligament probably amphidetic, the portion in front of the beaks, 

however, much reduced, penetrating the hinge plate 

behind the beaks; area of attachment behind the beaks 

somewhat V-shaped, the two arms of the V separated 

by a shelly plate projecting from underneath the umbones. Dentition much concentrated; anterior cardinal of right valve apparently atrophied; posterior 

cardinal subumbonal, very stout and deltoid; anterior

and posterior cardinals of left valve diverging on either 

side of the deep, triangular, subumbonal socket; the 

anterior more laminar, the posterior stouter at the 

base; laterals very short and close to the umbones, 

reduced to an anterior and a posterior dentate process 

in the left, received in corresponding sockets of the 

right. Characters of interior obscure. Adductor 

muscle scars apparently small, the anterior placed 

down near the anterior basal angle, the posterior much 

higher. Pallial line and sinus obscure.

Dimensions: Left valve (immature paratype), 

altitude, 7 millimeters; latitude, 10.2 millimeters; 

semidiameter, 2.6 millimeters. Right valve (type), 

altitude, 9.5 millimeters; latitude, 12.2 millimeters; 

semidiameter 3.7 millimeters.

Types: U. S. Nat. Mus. No. 353932.

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

The immature forms are much less elevated than 

the adults.

Donax trueloides is much higher relatively and more 

flexuous than any other Alum Bluff Donax.

Occurrence: Chipola formation, locality 221 lr.

Donax sp.

A fragment of a large species, possibly 20 millimeters 

long and 30 millimeters wide, was collected near Shell 

Bluff on Shoal River. It is totally unlike any of the 

described forms from the Atlantic Coastal Plain and 

suggests rather Donax denticulata Linnaeus or Donax 

striata Linnaeus, of the Recent West Indian fauna, 

a group recognized also in the Pliocene of Costa Rica.

Occurrence: Shoal River formation, locality 3733r.

Section FARADONAX Cossmann

1910. Paradonax Cossmann. Cossmann and Peyrot, Conchologie neogenique de 1'Aquitaine, vol. 1, p. 293.

Type: Donax transversa Deshayes. (Miocene of 

southern France.)

The section is characterized by the trigonal to 

subcylindrical outline, the subcutaneous radial sculpture, the small, concentrated hinge, and the feeble or 

obsolete anterior laterals.

Donax aldrichi Gardner from the Oak Grove sand, 

bears a remarkable resemblance to the type species 

a resemblance that is probably not without significance, for Donax transversa Deshayes and its allies 

were widely distributed in southern Europe through 

Miocene and possibly Pliocene time.

Donax (Paradonax) aldrichi (Dall MS.) Gardner, n. sp.

Plate XXXII, Figures 14-15

Shell rather small, very highly polished, subcylindrical in outline, over twice as wide as it is high; 

the umbones placed near the posterior fourth. Anterior end accordingly very much produced; the anterior 

dorsal margin rudely parallel to the base, the anterior
TELLINACEA. SOLENACEA, MACTRACEA, MY ACE A, MOLLUSCOIDEA 213

lateral margin quite strongly rounded. Posterior 

end acutely rostrate, the posterior lateral extremity 

bowed out slightly from the umbones to the rostral 

angle, rounding abruptly into the base. Umbones 

angular, inconspicuous, the tips acute and opisthogyrate. Both lunule and escutcheon suggested but 

not defined. Prodissoconch much less elongated 

transversely than the conch, smooth, polished. A 

faint but very uniform and regular radial lineation 

developed over the disk of the' conch from directly 

behind the anterior curvature to directly in front of 

the rostrum, strengthening slightly toward the ventral margin; area behind the rostrum sculptured with 

concentric ridges which become increasingly acute 

and more distantly spaced ventrally. Ligament 

amphidetic, the portion in front of the beaks linear 

and much reduced; the area of attachment behind 

the beaks very short and irregular in outline, invading the hinge plate; left valve only known. Dentition much concentrated; cardinals two in number, 

the anterior the more robust, diverging on either side 

of a deep, triangular, subumbonal socket; short, 

dentate lateral processes also developed on either 

side of the cardinals, the anterior lateral separated 

from the cardinal only by a shallow sulcus; the posterior a little more removed. Characters of interior 

obscure. Adductor scars rather large and rudely semielliptical in outline. Pallial line running closer to the 

base posteriorly than anteriorly. Pallial sinus rudely 

quadrate, its lateral extremity approximating the median vertical, coalescent ventrally. Inner margins 

strongly fluted in harmony with the external radials.

Dimensions: Altitude, 7.5 millimeters; latitude, 

15.8 millimeters; semidiameter, 2.2 millimeters.

Type: U. S. Nat. Mus. No. 109199.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The species is known only from a single left valve 

remarkable for its high polish, transversely elongated 

subcylindrical outline, and sharp concentric sculpture 

behind the acute posterior keel.

The similarity between Donax aldrichi and the type 

species of the section, Donax transversa Deshayes, 

from the Miocene of southern France, is most striking. 

In outline, dimensions, and general appearance of 

both the outer and inner surfaces the two shells are 

practically identical. The one character by which 

they may be readily separated is the greater prominence and isolation of the left anterior lateral of the 

American species.

Occurrence: Oak Grove sand, locality 2646 r.

Donax (Paradonax) valhosierr Gardner, n. sp.

Plate XXXII, Figures 16, 17

Shell small, rather thin, fragile, not strongly 

inequilateral, moderately inflated, compressed anteri8(i719ti O 50 5 (142-E)

orly, obtusely rostrate posteriorly. Umbones small, 

inconspicuous, the tips acute and feebly opisthogyrate, 

slightly posterior. Neither lunule nor escutcheon 

defined. Dorsal margins diverging from the umbones 

at an angle of a little more than 90°, the anterior 

more gently sloping than the posterior, particularly 

in the adult forms, and also more produced. Anterior 

lateral margin rather sharply rounded. Posterior 

lateral margin broader. Base line very feebly arcuate. 

External surface smooth and polished with a subsurficial radial lineation developed over the greater 

part of the disk, strongest medially. Ligament 

amphidetic, reduced and sublinear anteriorly; the 

posterior area of attachment irregular; the nymph 

somewhat spoon-shaped. Dentition much concentrated; anterior cardinal of right valve simple, laminar; 

posterior cardinal subumbonal, stout, deltoid, rnesially 

sulcate; cardinals of left valve diverging on either 

side of the deep, triangular, subumbonal pit; the 

posterior cardinal a little heavier than the anterior; 

a dentate lateral developed on either side of the left 

cardinals and very close to them; corresponding 

sockets excavated in the right valve. Interior slightly 

thickened laterally toward the umbones. Adductor 

scars irregular in outline, the anterior smaller and 

closer to the base. Pallial line moderately removed 

from the hinge; the sinus deep, covering about 

two-thirds of the distance to the anterior adductor, 

partially coalescent below. Inner margins finely 

crenate in harmony with the subsurficial radials.

Dimensions: Right valve, altitude 7 millimeters; 

latitude, 12 ± millimeters; semidiameter, 2.3 millimeters.

Type: U. S. Nat. Mus. No. 353931.

Type locality: No. 5079, half a mile below Shell 

Bluff, Shoal River, Walton County, Fla.

Donax valhosierr is decidedly less inequilateral 

than any other Alum Bluff Donax and approaches 

more closely to the dominant forms of the later 

Miocene and Pliocene, such as Donax jossor Say and 

Donax emmonsi Dall.

Occurrence: Shoal River formation, locality 5079 p .

Family PSAMMOBIIDAE Dall 

Genus PSAMMOBIA Lamarck

1818. Psammobia Lamarck, Histoire naturelle des animaux

sans vertebres, vol. 5, p. 511. 

1822. Psammobia Bowdich, Elements of conchology, pt. 2,

p. 6, pi. 1, fig. 10.

Type: Tellina feroensis Gmelin. (Recent off the 

shores of northern Europe.)

Shell moderately large, transversely elongated, 

slightly gaping, rudely elliptical in outline, more or 

less rostrate posteriorly; umbones subcentral; dorsal 

margins gently sloping; anterior extremity broadly 

rounded; posterior extremity more or less truncate;
214 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

surface sculpture usually feeble and irregular upon 

the anterior and medial portions of the disk, stronger 

and more uniform upon the posterior area; ligament 

strong, external, opisthodetic; dental formula variable usually two subumbonal cardinals in each 

valve, the posterior cardinal of the right valve and 

the anterior cardinal of the left often feebly sulcate; 

pallial line distant from the margin; pallial sinus profound, the ventral margin wholly or in part coalescent 

with the pallial line.

The Recent species are not very numerous, but 

they have a wide distribution in the shallow waters.

The genus is represented in the Alum Bluff group 

by only a single rare species, which is, however, found 

in both the Chipola and the Shoal River formations.

Psammobia bowdichi Gardner, n. sp.

Plate XXXII, Figures 23-26

Shell of moderate dimensions for the group, highly 

polished when fresh, rather thin and compressed, 

transversely elliptical in outline, obscurely rostrate 

posteriorly. Neither lunule nor escutcheon defined. 

Umbones subcentral or slightly anterior, low, compressed, acutely pointed at their tips, orthogyrate, 

proximate. Both anterior and posterior dorsal margins very gently declining, the posterior a little higher 

than the anterior. Lateral margins very broadly 

rounded. Base line nearly horizontal. Surface sculpture, for the most part, incremental in character, the 

medial portion of the shell smooth excepting for 

occasional growth striae, which become more pronounced ventrally and anteriorly, the growth stages 

indicated behind the rostrum by acute, regularly 

spaced concentric ridges, tending to develop into overlapping laminae, the free edges ventrally inclined. 

Ligament external, opisthodetic, the nymph produced 

about half the length of the posterior dorsal margin, 

the groove narrow but deep. Dentition reduced to 

two proximate cardinals in each valve springing from 

directly beneath the umbones, those of the right 

valve elevated, the posterior a little more robust than 

the anterior and feebly sulcated upon its upper surface. Teeth imperfectly preserved in the left valve, 

apparently a little more slender than those of the 

right valve. Inner surface thickened slightly within 

the area of the attached mantle. Adductor scars distinct, irregular in outline, not very high, placed rather 

high up under the dorsal margins. Pallial sinus distinct, ovate, covering a little more than half the intervening distance between the two adductors, the dorsal 

margin slightly curved, the lateral extremity broadly 

rounded, the ventral margin partially coalescent. 

Pallial line removed from the base.

Dimensions: Left valve, altitude, 11.5 millimeters; 

latitude, 19.5 millimeters; semidiameter, 3 millimeters.

Type: U. S. Nat. Mus. No. 353933.

Type locality: No. 2213,1 mile below Bailey sJFerry, 

Calhoun County, Fla.

Imperfect individuals attaining an altitude of 35 

millimeters are found in both the Chipola and Shoal 

River formations.

Psammobia bowdichi Gardner n. sp., has been confused in the check lists and collections with Psammobia 

papyria Conrad, a Jackson species with a well-defined 

Tellina-like sculpture of overlapping lamellae dorsally 

inclined.

The three imperfect valves from Shoal River are 

tentatively referred to P. bowdichi, though they may 

prove subspecifically distinct. They seem to be a 

little more elongated transversely and somewhat more 

compressed than the Chipola individuals. The Shoal 

River forms exhibit a rather strong concentric banding 

inherited possibly from the original color pattern.

Psammobia bowdichi has been referred to Psammobia 

s. s. rather than to Gobraeus, the subgenus to which 

most of the fossil species are assigned.

Occurrence: Chipola formation, localities 2212r, 

2213r. Shoal River formation, locality ?3733r.

Genus TAGELUS Gray

1847. Tagelus Gray, Zool. Soc. London Proc., vol. 15, p. 189. 

1817. Siliquaria Schumacher, Essai d'un nouveau systeme des

habitations des vers testaces, p. 129. 

Not Siliquaria Bruguiere, 1789, Encyclopedic m<§thodique,

vol. 6 (Histoire naturelle des vers), p. 15.

Type: Solen gibbus Spengler. (Fossil from the late 

Miocene to Recent from Cape Cod to Brazil and on 

the west coast of Africa.)

Dall, 10 in 1900, described this genus as follows:

Beaks median or subposterior; teeth two in each valve, simple 

pedunculate; valves without constriction or clavicle, straight; 

pallial sinus deep, reaching to or beyond the beaks; posterior 

adductor scar rounded; pallial sinus with the ventral part 

partially coalescent with the pallial line; situs estuarine or 

marine.

The Recent forms are separated from certain members of the Solenidae which they closely resemble by 

the hinge characters and the very much longer siphons. 

The genus has been recognized in rocks -as old as the 

Cretaceous.

The ugh the number of species referable to Tagelus 

is very small, yet this genus includes two species of 

remarkable longevity one the type of Tagelus s. s., 

the other of the subgenus Mesopleura. Tagelus gibbus 

Spengler has not been found in strata older than the 

Yorktown formation, but the ancestors of Tagelus 

divisus Spengler were flourishing certainly as early as 

Chipola time.

Subgenus MESOPLEURA Conrad

1867. Mesopleura Conrad, Am. Jour. Conchology, vol. 3, app., 

p. 23.

Type: Mesopleura (Solen) bidentata Spengler = Solen 

divisus Spengler. (Pliocene and Pleistocene of the

10 Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 5, p. 982.
TELLINACEA, SOLEXACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 215

southeast coast and Recent from Massachusetts to 

the West Indies.)

The subgenus is characterized by the presence of an 

internal rib. This is apparently an archaic character, 

as it is stronger in Miocene forms than in the Recent 

and stronger in the young than in the adults.

Tagelus (Mesopleura) sp. cf. T. divisus (Spengler) 

Plate XXXII, Figure 27

1794. Solen divisus Spengler, Skrivter af Naturhistorie Selskabet, vol. 3, p. 96, Kioebenhavn. 

1900. Siliqua subaequalis Gabb. Dall, Wagner Free Inst. Sci.

Trans., vol. 3, pt. 5, p. 956 (part). 

Not Siliqua subaequalis Gabb. Am. Philos. Soc. Trans.,

vol. 15, p. 247, 1873.

Shell rather small for the group, thin, gaping, subcylindrical, equivalve, slightly inequilateral, moderately compressed, somewhat flattened laterally but not 

rostrate. Umbones inconspicuous, orthogyrate, proximate, slightly anterior. Anterior end the shorter, 

obtusely truncate at its extremity. Posterior end 

produced, broadly but asymmetrically rounded. Base 

line nearly rectilinear. External surface smooth except for incrementals, least feeble upon the lateral 

areas. Ligament external, mounted on a linear nymph 

a little less than one-half as long as the posterior dorsal 

margin. Cardinals two in number in each valve, 

springing from beneath the umbones; the anterior 

cardinal of the right valve long, slender, recurved at the 

pointed tip, flattened on the inner surface; posterior 

right cardinal also long and recurved and flattened 

upon its inner surface but spatulate, the extremity 

expanded horizontally and feebly sulcated; anterior 

cardinal of left valve thin and laminar to fit between 

the flattened and proximate inner surfaces of the right 

cardinals; posterior left cardinal also laminar but more 

nearly parallel to the dorsal margin than to the anterior 

cardinal. Laterals not developed. Internal rib 

sharply defined dorsally, widening slightly and evanescing toward the base. Adductor scars distinct, 

rather large and irregular, set high up under the dorsal 

margins. Pallial line distinct, rather far removed 

from the base. Pallial sinus ovate, expanded at its 

extremity, almost but not quite touching the inner 

rib, coalescent ventrally with the pallial line. Margins 

very thin.

Figured specimen: U. S. Nat. Mus. No. 27437.

In Siliqua, to which these fragments have been 

referred in previous check lists, the posterior right 

cardinal is elongated parallel to the dorsal margin and 

received between two horizontal laminae in the left 

valve. There are, in addition, in the left valve two 

laminar subumbonal cardinals, all of them quite distinct from the Tagelus teeth. In Siliqua the pallial 

sinus is short and broad; in Tagelus it is very deep.

The Chipola form is well represented by fragments, 

but no perfect individuals are available. There is only

one character in which it seems to differ from the 

Recent species namely, the strength of the internal 

rib. In the Miocene type this rib, though it is slightly 

broader and less elevated away from the umbones, is 

sharply defined as far as the pallial line. In the 

Recent species both the rib and the streak of yellowishbrown color that defines the rib externally and internally often disappear halfway between the umbones 

and the ventral margins. By whatever name these 

forms are called, they represent a remarkably persistent race. Tagelus gibbus, the type of the genus, 

has itself existed unchanged since the late Miocene. 

It is rather common in the Miocene cliffs below Yorktown, and in the waters at the base of the cliffs the 

Recent representatives are flourishing.

The Shoal River species, on the other hand, is certainly distinct. The shell is larger and thinner, and 

the pallial sinus is not expanded at its extremity.

Occurrence: Chipola formation, localities 2564P, 

3419 C, 2211 r.

Tagelus (Mesopleura) sp.

Fragments of a second member of the Tagelus group 

are present in the Shoal River formation. They 

indicate a species differing from both the Chipola 

form and the recent T. divisus (Spengler) in the larger, 

thinner shell and the narrower pallial sinus. In the 

other forms of the Tagelus divisus group the dorsal 

margin is decidedly arcuate and the outline of the 

sinus decidedly ovate. In the Shoal River species 

the dorsal margin of the sinus is nearly or quite parallel 

to the ventral margin, and its lateral extremity is 

symmetrically rounded.

Occurrence: Shoal River formation, localities 3856 p , 

5192 r.

Genus PSAMOSOLEN Risso

1826. Psammobia Risso, Histoire naturelle de 1'Europe me'ridionale, vol. 4, p. 375. 

Not Psammobia Risso, 1826, idem, p. 350. 

1826. Psamosolen Risso, idem, vol. 5, Index corrigendum, p. 397.

Type: Solen strigilatus Linnaeus. (Recent in the 

Mediterranean.)

Psamosolen has been commonly written with two 

m's. The single m was possibly an error on the part 

of Risso, but the wTord as it stands in the index, the 

only place in his volume in which it appears, is written 

Psamosolen. The correction of the popular misspelling 

was made by Woodring n in 1925.

Shell thin, gaping, often rather high, subcylindrical 

in outline, obtusely truncate laterally; umbones low, 

subcentral or anterior; external sculpture incised, 

oblique, similar in character to that of Divaricella, 

more rarely concentric; ligament external, opisthodetic; two elevated, often recurved, subumbonal cardinals in each valve; laterals not developed; adductor

11 Woodring, W. P., Miocene mollusks from Bowden, Jamaica: Carnegie Inst. 

Washington Pub. 366, p. 182, 1925.
216 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

scars dorsal in position; pallial sinus deep, not coalescent ventrally.

The characters of the hinge and the sinus ally 

Psamosolen with Tagelus and the Psammobiidae rather 

than with Solen and the Solenidae.

Psamosolen has had a meager distribution in the 

temperate and tropical waters from the Tertiary 

period on. A single species in the Chipola known from 

rather numerous fragments and a juvenile from Shoal 

River establish the presence of the genus in the upper 

and lower beds of the Alum Bluff group.

Psamosolen aldrichi Gardner, n. sp.

Plate XXXIII, Figures 2-3

1900. Psammosolen vicksburgensis Aldrich. Dall, Wagner Free

Inst. Sci. Trans., vol. 3, pt. 5, p. 960 (part). 

Not Solecurtus vicksburgensis Aldrich, Cincinnati Soc.

Nat. Hist. Jour., vol. 8, p. 145, 1885. 

Not Macha vicksburgensis Aldrich, Alabama Geol. Survey 

Bull. 1, p. 37, pi. 2, fig. 1, 1886.

Shell thin, gaping both laterally and dorsally, subcylindrical in outline, about twice as wide as it is high, 

moderately and evenly compressed. Umbones low, 

flattened, the tips proximate and orthogyrate, slightly 

anterior, produced a little beyond the dorsal margin. 

Lunule and escutcheon not defined. Anterior dorsal 

margin very gently declining. Posterior dorsal margin nearly rectilinear and parallel to the base. Lateral 

margins broadly rounded. Prodissoconch minute, 

flattened, smooth, shining. Characteristic incised 

sculpture developed over the medial and posterior 

portions of the conch, ceasing abruptly along a line 

dropped from directly in front of the umbones and 

inclined slightly forward; anterior portion ornamented 

only with rather strong incrementals and obscure and 

irregular radials; sculpture upon medial and posterior 

portions fine and quite regular, the free edges of the 

grooves inclined medially and running at a high angle 

to the base, sinuous posteriorly, sharply upcurved 

along an imaginary diagonal from the umbones to the 

posterior basal margin. Ligament external, opisthodetic, attached to relatively short but heavy nymphs. 

Cardinals two in number in each valve, elevated and 

slightly recurved, the anterior tapering subacutely, 

the posterior laminar and oblique to the dorsal margin; 

anterior cardinal of left valve also laminar and somewhat twisted; the posterior cardinal much reduced 

and usually broken away even in the Recent shells; 

the heavier teeth medial and clasping in the closed 

valve; the more slender teeth anterior and posterior. 

Inner surface strengthened by feeble and irregular 

radials and concentric corrugations. Adductor scars 

and pallial sinus obscure. Adductors close to the 

dorsal margin, irregular in outline, the anterior larger. 

Pallial sinus rather narrow but produced beyond the 

beaks.

Dimensions: Altitude, 15± millimeters; latitude, 

35 ± millimeters; semidiameter, 4.5 millimeters.

Type: U. S. Nat. Mus. No. 353934.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

It is regrettable that the material is so fragmentary, 

but because of the confusion in the synonymy and the 

chances against finding so thin and delicate a shell 

perfectly preserved it has seemed unwise to await 

more suitable material.

The type of P. vicksburgensis Aldrich (PI. XXXIII, 

fig. 1) has been kindly loaned by Johns Hopkins University. It represents a smaller, more compressed 

species, more elongated transversely. The surface is 

much worn, and the details of the sculpture are rather 

obscure. The anterior area is, however, much 

narrower than in the Alum Bluff form. The oblique 

groovings are certainly continued well over the anterior basal angle, whereas in P. aldrichi they disappear 

abruptly along a line which falls almost horizontally 

from the umbones. This character is constant in all 

the individuals examined. The Bowden form, which 

has also been included under P. viclcsburgensis, is apparently closer to the Vicksburg than to the Alum 

Bluff species.

Psamosolen aldrichi is remarkable for the fineness 

and uniformity of the ornamentation. In outline it 

suggests Psamosolen sanctae-marthae D'Orbigny, of 

the Recent fauna, a species with a coarser grooving 

developed over a larger area.

I have the pleasure of naming this interesting form 

in honor of Truman H. Aldrich, of Birmingham, Ala., 

who has kept the love for natural science so often 

obscured in these days of high specialization.

Occurrence: Chipola formation, locality 2213P.

Psamosolen sp.

A single juvenile suggesting Psamosolen cumingianus 

Dunker more closely than any other species described 

from the east coast was collected from Shell Bluff, on 

Shoal River in Walton County, Fla. It is decidedly 

more than half as wide as it is high, strongly rounded 

laterally, and sculptured with about a dozen irregular 

groovings.

Occurrence: Shoal River formation, locality 3742r.

Superfamily SOLENACEA Lamarck

Dall 12 gives the following description:

Dwellers in soft bottom, narrow, elongated, modified for 

burrowing, with anterior and posterior ends both gaping; foot 

elongated, distally modified to serve as a piston or stilt within 

the burrow; aorta with postventricular dilation; hinge without 

lateral laminae.

12 Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 3, p. 555, 1895.
TELLINACEA, SOLENACEA, MACTRACEA, MY ACE A, MOLLTISCOIDEA 217

Family 80LENIDAE Leach

Dall 13 describes this family as follows:

Shell substance as in Tellina, but the external layer showing 

its cellular structure more clearly; with a pronounced epidermis; 

valves equal, free, usually truncate at both ends, and more or 

less inequilateral, with low beaks, smooth margins, smooth or 

feebly sculptured, not rostrate; adductor scars narrow, elongate, 

dorsally distributed, pedal distinct; pallial sinus small in species, 

with anterior umbones and vice versa; ligament and resilium 

external, parivincular, seated on nymphs; area obscure or none; 

hinge plate hardly developed; hinge often with a thickened ray 

crossing the valves and serving as a buttress; cardinals varying 

from one to four in each valve, usually a single slender radial 

laminar cardinal in the right, and two in the left valve; with 

or without one or two placed parallel with the hinge margin, 

simulating laterals; radial teeth usually more or less pedunculated, rarely bifid.

Genus SOLEN (Linnaeus) Lamarck

1758. Solen Linnaeus, Systema naturae, 10th ed., p. 672.

1777. Solen Scopoli, Introductio ad historian! naturalem sistens 

genera lapidum, plantarum et animalium hactenus 

detecta caracteribus essentialibus donata in tribus 

divisa sub inde ad legas naturae, Prague. (No type 

selected.)

1799. Solen Lamarck, Prodrome d'une nouvelle classification 

des coquilles: Soc. hist. nat. Paris M6m., p. 83.

Type: Solen vagina Lamarck (not Solen vagina 

Linnaeus) Solen marginatus Pulteney. (Recent on 

the European shores from Scandinavia to the Mediterranean and possibly to the Red Sea.)

Shell long, narrow, generally straight, subcylindrical; umbones anterior, subterminal; external surface polished, smooth or feebly sculptured; ligament 

external, elongated; hinge armature limited to a 

single cardinal in each valve; anterior adductor muscle 

impression very long and narrow, near and parallel 

to the dorsal margin; posterior impression semielliptical; pallial line distinct, sinus shallow.

Indubitable species of this genus are known to 

occur in the Triassic and some doubtful mid-Paleozoic 

forms have been included under it by certain authors. 

The recent species are about 50 in number and worldwide in distribution. The majority are littoral. At 

the approach of danger they burrow rapidly downward by means of the alternate extension and contraction of the foot, which serves first as a blade to 

cut through the sand and then as an anchor to which 

they may hold until the valves can be pulled down.

The genus has been recognized as edible since the 

days of Aristotle, and the clam fishers along the French 

coasts use the same type of tackle to-day as that 

employed by the ancient Greek fishermen.

The genus is known from the Alum Bluff by a single 

splendid species restricted to the two lower horizons.

» Dall, W. H., op. cit., pt. 3, p. 555.

Solen amphistemma Dall

Plate XXXIII, Figure 4

1900. Solen amphistemma Dall, Wagner Free Inst. Sci. Trans., 

vol. 3, pt. 5, p. 952, pi. 39, fig. 8.

Dall describes this species as follows:

Shell large, short, straight, rather con vox; anterior end 

obliquely truncate, with the inner margin thickened, but no 

external furrow; posterior end squarely truncate; basal parallel with the dorsal margin; exterior smooth, except for incremental lines; beaks inconspicuous, slightly behind the anterior 

dorsal angle of the valve, the teeth normal, the nymphs narrow, 

elongate, not prominent; anterior adductor scar irregularly 

reniform, posterior rounded triangular; the pallial sinus shallow. Longitude of shell 112, altitude 27.5, diameter 18 millimeters.

This very fine species is almost invariably in fragments. It 

does not closely approach any other of our Solens.

Type: U. S. Nat. Mus. No. 135901.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The incremental sculpture strengthens abruptly 

along the diagonal from the umbones to the posterior 

basal margin. In front of this line the incrementals 

are scarcely perceptible except perhaps toward the 

base which they parallel. Behind the diagonal they 

turn and abruptly develop into a somewhat irregular 

but well-defined grooving parallel to the posterior 

and lateral margins and at right angles to the dorsal 

margin. The single tooth in each valve is flattened 

on its inner surface and moderately broad at the 

base.

Solen amphistemma is common in the Chipola and 

present in the Oak Grove, but no indication of the 

genus has yet been found in the Shoal River 

formation.

Occurrence: Chipola formation, localities 2212 P, 

2213p , 3419p, 7151 r, ?7468P. Oak Grove sand, 

localities 2646P, 7054r.

Genus ENSIS Schumacher

1817. Ensis Schumacher, Essai d'un nouveau systeme des 

habitations des vers testace"s, p. 143.

Type: Ensis magnus Schumacher. (Recent on the 

north European shores.)

Valves thin, scabbard-shaped, slightly gaping, 

usually somewhat arcuate; umbones flattened, subterminal; ligament external, opisthodetic; hinge of 

right valve armed with one vertical and one horizontal 

lamelliform cardinal, that of the left valve with two 

proximate vertical cardinals and one horizontal; 

anterior adductor impression conspicuous, elongated 

in the general direction of the major axis; pallial line 

rather distant from the ventral margin, sinuate 

posteriorly.
218 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Ensis resembles Solen externally, but internally it 

differs in the possession of two vertical cardinals in the 

left valve instead of a single one, as in Solen.

The genus has not been found in beds older than the 

beginning of the Tertiary, though the family has been 

traced back into the Paleozoic. The Recent representatives are confined to a few prolific species and are 

among the most interesting of the inhabitants of the 

soft inshore muds and sands. They are surprisingly 

agile, and by means of the strong extensile foot they 

are able to retreat into their burrows with astonishing ease and rapidity. It is doubtless this unusual 

agility that has enabled these thin, gaping forms to 

continue to flourish in the midst of enemies through 

so many thousands of years.

Ensis is indicated in the Oak Grove sand and the 

Shoal River formation by numerous fragments but 

by no individuals sufficiently perfect to make it 

possible to establish the relationships definitely.

Ensis sp. cf. E. directus (Conrad)

Plate XXXIII, Figures 5-6

1842. Solen ensis Lamarck [not Linnaeus]. Conrad, Nat. 

Inst. Washington Proc., vol. 2, p. 191.

1843. Solen directus Conrad, Acad. Nat. Sci. Philadelphia 

Proc., vol. 1, p. 325 (and authors).

Conrad, in 1843, described this species as follows:

Linear, straight, except toward the summit, where it is 

slightly recurved, gradually widening from the hinge downward; basal margin rounded slightly toward the posterior 

extremity; anterior margin obliquely truncated, not reflected; 

cardinal teeth, one in the right valve, compressed, in the opposite valve two, the superior one very small and near the extremity, the other somewhat distant, elevated, robust, slightly 

recurved. Length, 4 inches.

Type locality: Neuse River below New Bern, N. C.

Conrad's erroneous description of the hinge characters of this species is due, doubtless, to the imperfections of his type. The armature of the right valve 

consists of a vertical cardinal and, back of it, a rather 

broad, grooved horizontal tooth, which projects, 

shelf-like, from the hinge margin; in the left valve, 

two strong vertical cardinals, recurved at their pointed 

tips and separated by a deep, narrow cleft; back of 

them, a grooved horizontal tooth bifid terminally, 

the extremities slightly incurved toward each other. 

In addition to the true teeth, which are common to 

all species of the genus, there is a rude denticle in 

front of the vertical cardinal in the right valve, a 

specific diagnostic feature which serves to separate it 

from the closely allied Ensis ensiformis of Conrad. 

The diagnostics, aside from the hinge characters, are 

the posterior and anterior truncations the former 

almost straight, the latter straight or slightly oblique 

 and the large size which the species often attains. 

The greatest dimension of the recent forms along the

northern part of the east coast may reach 8 or 9 

inches. The Tertiary and Recent forms of the 

warmer waters run decidedly smaller. The remnants 

of the old color pattern are discernible in many of the 

later Tertiary forms, included between a line very 

slightly concave upward, extending from the anterior 

dorsal margin to the posterior ventral and another 

line, also concave upward, extending from the anterior 

dorsal to the posterior dorsal margin. Within this 

narrow wedge-shaped area incrementals, often tinged 

with brown, are visible in the better-preserved individuals. As these are parallel to the posterior margin 

they serve to indicate the former outline, even in the 

broken shells. In the ventral anterior portion and 

a small arcuate area along the dorsal margin the coloring is absent and is replaced in the recent shells by a 

heavy olive-green epidermis; in these sections the 

incrementals are less strong and run approximately 

parallel to the ventral and dorsal margins.

The recent forms are numbered among the edible 

mollusks. The razor clams, as they are known in 

popular parlance, are, however, very difficult to capture, because by means of their strong, flexible foot 

they can burrow downward more rapidly than an 

average man can dig. The species is abundant along 

the sandy and muddy beaches of the east coast from 

Labrador to the Florida Keys.

Small, thin fragments representing ancestral types of 

this species and possibly of E. ensiformis, as well, are 

by no means rare in the Oak Grove and the Shoal 

River. They may be specifically identical with Ensis 

directus in whole or in part. Certain individuals from 

the Shoal River, however, have more the aspect of 

Ensis ensiformis. At all events the group was well 

established in the Alum Bluff, and the exact determinations of the forms must await better material.

Occurrence: Oak Grove sand, localities 2646C , 

7054D . Shoal River formation, localities 5079C , 5194r.

Superfamily MACTEACEA Gray

Ball's statement 14 of the results of his extensive 

studies on the Mactracea is given below:

The essential parts of a true mactroid hinge are as follows: 

In the left valve, an anterior and posterior lateral lamina, and 

a bifid or A-shaped cardinal tooth in front of a pit for the resilium; above the latter a scar or surface of insertion for the ligament. In the right valve, two anterior and two posterior laminae, 

between which the laterals of the opposite valve are received; 

two lamellar cardinal teeth, inclined to each other at an angle 

above and usually more or less solidly united at this line of 

junction, below which the cardinal of the opposite valve fits; 

behind them the chondrophore, and above it the scar of the 

ligament. The ligament and cartilage start in the youngest 

stage of the shell from a point immediately under the beaks. 

Once started, each remains continuous between the two valves 

of the shell and persistent, so that as they lengthen with growth

i< Ball, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 4, pp. 862-863, 1898.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 219

the portion below each umbo remains intact. According to the 

amount of expansion of the shell margin between the beaks and 

the direction of growth of the valves, the form of the adult cartilage and ligament may be crescent-shaped, with a posterior 

convexity; sagittate, like a barbed arrowhead; or lanceolate, 

like a leaf-shaped spearhead. The distance between the points 

of the barbs is determined dynamically by the distance between 

the umbones of the valves: when they are widely separated, as 

in Mactra spengleri, we have the most extreme crescent shape; 

when they are but slightly separated, the sagittate form ensues; 

when the unbones are close together, the species must have a 

lanceolate ligament. A steep slope of the dorsal shell margin 

backward from the umbonal region necessitates a short ligament, while a nearly horizontal long posterior cardinal margin 

promotes a long and narrow ligamentary connection. The correlations are purely dynamic. There is little doubt that the 

existence of a separate resilium and ligament is due to mechanical 

forces acting on a thick ligament. * * * Why the ligament 

should become embedded in the cardinal border so as to become 

subject to these forces is not so clear but is probably accounted 

for in part by the fact that the hinge line is rigid in proportion 

to its length, and, in general, if high up in the dorsal arch it 

must be short and can gain length only by descending. Whatever the reason may be, it is doubtless analogous to that which 

would account, in a species where ligament and resilium have 

become fully differentiated, for the further subsidence of the 

ligament until it, in its turn, may be wholly submerged below 

the cardinal margin, so that the latter closes over it, leaving no 

ligamentary substance whatever external to the shell. In the 

Mactridae every stage of this process may be observed, from the 

condition where we have a marginal external ligament walled 

off by a lamina of shell from the resiliary pit to one where ligament and resilium occupy different portions of a single cavity, 

wholly invisible from the exterior when the valves are closed.

Family MACTRIDAE Gray

Subfamily MACTRINAE Ball

Genus MACTRA Linnaeus

1766. Mactra Linnaeus, Systema naturae, 12th ed., p. 1125. 

1799. Mactra Lamarck, Prodrome d'une nouvelle classification 

des coquilles: Soc. hist. nat. Paris Mejn., p. 85.

Type: Mactra stultorum Linnaeus. (Recent on the 

west European shores from Norway southward to the 

Mediterranean and possibly to the Red Sea. Fossil in 

the Crag.)

Dall, 15 in 1898, described this genus as follows:

Dentition normal in number and distribution of teeth; 

ligament set off by a shelly lamina rising between chondrophore 

and ligament; cardinals generally coalescent above; laterals 

smooth or finely granular.

A genus prominent in the mollusc an faunas since 

Tertiary tune. The Recent species about 150 in 

number are to be found, for the most part, along the 

sandy beaches and in the shallow waters of the tropical 

seas.

The extensive later collections have yielded a large 

amount of new mactroid material of the less modern 

Spisula type but only a fragment or two of the true 

Mactra. Possibly the slight cooling of the waters at 

the end of the Chipola epoch was sufficient to retard 

the development of the group temporarily. The

18 Dall, W. H., op. cit., pt. 4, p. 874.

Chipola species, Mactra chipolana Dall, is the earliest 

described member of the genus from the east coast 

fauna. The Oak Grove species, Mactra cymata, represents a distinct subgenus and is the precursor of a 

rather prominent Pliocene group. The genus has not 

been recognized in the Shoal River faunas.

Umbones not concentrically undulated.. Mactra chipolana Dall. 

Umbones concentrically undulated.

Mactra (Mactrotoma) cymata Dall.

Subgenus MACTRA s. s. 

Dall16 gives the following description:

Shell subequilateral, ovate-trigonal; spur distinct, roofing the 

apical part of the chondrophore; anterior laterals radiating 

from the anterior sinus, not confluent with the anterior arms of 

the cardinals, and the latter without accessory lamella; dental 

armature not concentrated.

The majority of old-world Mactras belong to this group, 

which is represented only by a single small species in the Caribbean and none on the Pacific shores of America.

Mactra chipolana Dall 

Plate XXXIII, Figure 7

1898. Mactra chipolana Dall, Wagner Free Inst. Sci. Trans., 

vol. 3, pt. 4, p. 892, pi. 27, fig. 19.

Dall describes this species as follows:

Shell rather thin, subovate, compressed, sculptured chiefly 

by lines of growth which are emphasized at short intervals by 

being slightly elevated; judging from recent shells, these lines 

in life bore fringes of epidermis; dorsal areas narrow, elongate, 

the anterior obscurely impressed, the posterior convex with the 

inner margin depressed, the outer margin marked by a slightly 

elevated line parallel to and outside of which at a short distance runs another which extends from the umbo to the posterior 

ventral margin, much as in Mactrotoma; interior rather smooth, 

the pallial sinus wide, rounded, and extending forward nearly to 

a vertical line from the beaks; hinge normal, the septum below 

the ligament inconspicuous, the laterals short and smooth, the 

left cardinal well developed, prominent; the accessory lamella 

thin and usually lost; the chondrophore not prominent, with 

slightly raised edges and a small apical roof, over which the 

ligament was sagittate. Longitude of a well-grown specimen 

about 45, altitude 35, semidiameter 12 millimeters.

Only fragments of the left valve of four individuals were 

obtained. The measurements are, therefore, only approximate. 

The shell represents the first step of transition from the S pis ula 

to the Mactra stage and is therefore intermediate in its characters 

between Spisula and Mactrotoma.

Type: U. S. Nat. Mus. No. 114650.

Type locality: No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

This is the earliest representative of Mactra s. s. reported from the east coast fauna.

Occurrence: Chipola formation, localities 2212r,

2213r.

Subgenus MACTROTOMA Dall

1894. Mactrotoma Dall, Nautilus, vol. 8, p. 23. 

1898. Mactrotoma Dall, Wagner Free Inst. Sci. Trans., vol. 3, 

pt. 4, p. 876.

" Dall, W. H., op. cit., pt. 4, p. 874.
220 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Type: Mactra fragilis Gmelin. (Recent on the 

east coast from Hatteras to Brazil.)

In 1894 Dall said: "Anterior left lateral tooth bidentate, right ventral tooth tridentate." In 1898 he 

gave this further description:

Shell subequilateral, elongate; with a thin, silky epidermis, 

posterior dorsal areas bordered by an impressed fasciole over 

which the epidermis is darker colored and differently wrinkled; 

beaks adjacent; pallial sinus large; valves convex, gaping 

markedly; ligament lanceolate; chondrophore large, shallow, 

apically roofed; anterior laminae issuing from the dorsal sinus; 

cardinals prominent, thin, their posterior arms projecting over 

the chondrophore; each anterior arm attended by a high 

accessory lamella in nearly the same plane, closely appressed in 

the right valve to the ventral lamina and in the left valve to the 

anterior lateral, so that, to a cursory inspection, the lamina 

appears tridentate and the tooth bidentate.

Section MICROMACTRA Dall

1894. Micromactra Dall, Nautilus, vol. 8, p. 40. 

1898. Micromactra Dall, Wagner Free Inst. Sci. Trans., vol. 3, 

pt. 4, p. 876.

Type: Mactra cali/ornica Conrad, not Deshayes. 

(Recent on the west coast from Vancouver to Central 

America.)

In 1894 Dall wrote: "Hinge like the typical section, beaks sulcate, shell small."

Mactra (Mactrotoma) cymata Dall 

Plate XXXIII, Figure 8

1898. Mactra (Mactrotoma) cymata Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 4, p. 893, pi. 33, fig. 23.

Dall describes this species as follows:

Shell small, thin, with prominent undulated beaks; subequilateral, rounded in front, rather pointed behind, the base 

moderately arcuate; surface sculptured with fine incremental 

lines, the umbones with ten or more distinct concentric ripples; 

the posterior slope moderately angulated or carinate anteriorly; 

pallial sinus rather short, rounded. Longitude 31.5, altitude 20, 

diameter 10 millimeters.

This species much resembles the Pliocene M. undula and 

differs from it chiefly in being smaller, more triangular, and 

more pointed behind.

Type: U. S. Nat. Mus. No. 107615.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The concentric undulation of the umbones sets this 

species apart from all the other Oak Grove mactroids.

Occurrence: Oak Grove sand, locality 2646r.

Genus SPISUIA Gray

1837. Spisula Gray, Mag. Nat. Hist., new ser., vol. 1, p. 372,

London, Edward Charlesworth. 

1898. Spisula Dall, Wagner Free Inst. Sci. Trans., vol. 3,

pt. 4, p. 878.

Type: Mactra solida Linnaeus. (Recent on the 

west coast of Europe. Fossil in the Crag.)

Shell often large and rather heavy, moderately 

inflated, subequilateral, ovate-trigonal in outline,

slightly produced and obscurely rostrate posteriorly 

Umbones prominent, subcentral. Surface smooth or 

incrementally sculptured. Ligament inset, not cut 

off from the resilium by a shelly ridge. Hinge armature strong. Right anterior and posterior cardinals 

coalescent under the umbones, the anterior arm near 

the dorsal margin, the posterior bordering the chondrophore and partly separating it from the socket in 

which the small inverted V-shaped cardinal of the 

left valve is lodged. Strong lateral teeth, developed 

within the dorsal margins of the left valve, received 

in the double sockets of the right; teeth and sockets 

both transversely striated in most of the groups. 

Muscle scars large and sunken in the heavier shells. 

Pallial sinus distinct, short, broadly U-shaped, nearly 

horizontal.

The absence of a shelly lamina between the chondrophore and the ligament separates Spisula from 

Mactra. Furthermore, the laterals of Mactra are 

smooth or finely granular, whereas those of Spisula are 

as a rule, transversely striated?

The genus extends well back into the Cretaceous, 

and though not abundantly represented in the recent 

seas, it is of almost universal occurrence.

It is extraordinary that the small heavy Mulinialike group so abundantly represented at the Oak 

Grove and Shoal River horizons should have no precursor in the Chipola formation. The two remaining 

species of Spisula referable to the section Mactromeris are more closely related to later Miocene forms 

than they are to each other, but of this group, too, 

there is no trace in the Chipola.

Laterals grooved; altitude of adult not exceeding 20 millimeters: 

Concentric sculpture feeble or absent.

Spisula (Hemimactra) densa Dall.

Concentric sculpture strongly and regularly developed 

toward the basal margin of the adult.

Spisula (Hemimactra) craspedota Gardner, n. sp. 

Laterals smooth; altitude of adult exceeding 20 millimeters: 

Shell very thin; posterior keel acute, outlined by an 

elevated thread.__ ..Spisula (Hemimactra) dodona Dall. 

Shell rather thick; posterior keel obscure.

Spisula (Hemimactra) valhosierr Gardner, n. sp.

Subgenus HEMIMACTRA Swainson 

1840. Hemimactra Swainson, Treatise on malacology, p. 369.

Type: Hemimactra gigantea Lamarck = Mactra solidissima Dillwyn. (Recent on the east coast from 

Labrador to Hatteras.)

Dall, 17 in 1898, described this group as follows:

Shell large, ovate-trigonal, with grooved laterals and rather 

concentrated hinge; the dorsal areas are not grooved and the 

anterior arm of the right cardinal is confluent with its ventral 

lamina; cardinals markedly compressed.

Hemimactra is a new-world type, for the most part, while the 

typical Spisula is old world, especially European, in its recent 

distribution, though represented in the American Tertiaries.

i7 Dall, W. H., op. cit., pt. 4, p. 878.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 221

Dall 18 says further:

This comprises a group of species which differ from the typical Spisula in being thinner, usually larger and more elongated, 

and agree with it in having the lateral laminae cross-striated, 

while in the section Mactromeris Conrad they are smooth, 

though this character is not one to which I attach any great 

importance.

Section HEMIMACTRA s. s.

Laterals grooved; cardinals compressed; anterior 

arm of right cardinal confluent with ventral lamina.

Spisula (Hemimactra) densa Dall 

Plate XXXIII, Figure 9

1898. Spisula (Hemimactra) densa Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 4, p. 900, pi. 27, fig. 22.

Dall describes this species as follows:

Shell small, solid, smooth, or concentrically sculptured, with 

fine incremental lines, and sometimes obscure radial striae near 

the margin; subtriangular, subequilateral; beaks small and 

low, hinge strong, the laminae sharply cross striated; pallial 

sinus rounded, small, and very short. Longitude 14, altitude 

9.5, diameter 6 millimeters.

This solid little species is stronger and larger than the majority of the Eocene forms and has the aspect of a Mulinia. Its 

height is less than in the allied Miocene types of about the 

same size, and its ends are more pointed.

Type: U. S. Nat. Mus. No. 135906.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The specimens found near Bainbridge, Decatur 

County, Ga., probably represent an allied but distinct species differing in the larger and usually higher 

and more compressed valves.

Spisula densa Dall averages shorter and higher than 

Spisula, craspedota, of the Shoal River fauna. The 

grooving is stronger upon the type of S. densa than 

upon most other individuals, and it is never so deep 

nor so regular as in the adult S. craspedota. This 

species is one of the most widespread and abundant 

of the Oak Grove bivalves, occupying a position in 

the Oak Grove similar to that held by Mulinia congesta Conrad in the later Miocene formations. The 

analogy to Mulinia congesta is more striking because 

of the similarity in outline and dimensions and the 

range of variation.

Occurrence: Oak Grove sand, localities 73386 p, 

?3385C , ?7148C , ?3396r, 2646pr, 5632% 563P, 

5633P, 7054°, 9961a , ?7055I>.

Spisula (Hemimactra) craspedota Gardner, n. sp.

Plate XXXIII, Figures 10-12

Shell small, rather heavy, trigonal, moderately inflated medially. Umbones gibbous, flattened upon 

their summits, the minute tips acute and prosogyrate, 

central or slightly anterior. Umbonal angle not far 

from 135°. Posterior slope a little steeper and usually 

a little more produced than the anterior. Anterior 

extremity rather narrow but smoothly rounded. Pos18 Idem, p. J

HtiTl'Jd O

teriof extremity sharply rounded or obtusely rostrate. 

Base line arcuate. Both anterior and posterior areas 

flattened, the posterior defined by a rather sharp keel. 

Lunule very large, extending almost the entire length 

of the dorsal margin, and nearly as wide medially as 

the area, smooth and circumscribed by a shallow 

impressed line. Escutcheon occupying a little more 

than half the posterior area, defined by the abrupt 

disappearance of the sculpture at its outer margin. 

Young and adolescent shell smooth except for incremental striae. Adult ornamented with a rather deep 

and regular grooving, developed first toward the 

anterior margin and increasing in prominence toward 

the base; an exceedingly fine radial lineation developed 

fortuitously upon the anterior keel. Area of ligament 

attachment very small, close under the dorsal margin. 

Chondrophore moderately large and deeply excavated, 

undercutting the umbones and roofed by the dorsal 

margin. Dentition robust, rather concentrated; anterior and posterior cardinals of right valve coalescent 

under the umbones, diverging almost at right angles, 

the anterior arm nearly parallel with the dorsal margin; cardinal of left valve sharply elevated above the 

margin, acutely /^-shaped, the posterior arm a little 

shorter and heavier than the anterior; posterior accessory lamella close to and parallel to the posterior arm, 

exceedingly thin and fragile and usually broken away; 

both right and left laterals well developed close to the 

umbones, the sockets of the right valve and the raised 

lamellae of the left finely striated transversely. 

Characters of interior distinct, the shell often slightly 

thickened over the area of the adherent mantle. Adductor scars distinct and relatively large. Pallial 

sinus shallow, linguiform.

Dimensions: Right valve (cotype), altitude, 10.4 

millimeters; latitude, 15.3 millimeters; semidiameter, 

4 millimeters. Left valve (cotype), altitude, 9.9 millimeters; latitude, 14.1 millimeters; semidiameter, 3.9 

millimeters.

Cotypes: U. S. Nat. Mus. No. 3524006.

Type locality: No. 5079, half a mile below Shell 

Bluff, Shoal River, Walton County, Fla.

Spisula craspedota occupies a position in the Shoal 

River fauna similar to that held by the closely allied 

S. densa Dall in the Oak Grove. The Shoal River 

species is a little lower relatively and more produced 

and pointed posteriorly. The most obvious difference 

is the development of a strong concentric grooving 

toward the ventral margins of the adults of S. craspedota. Both forms suggest the Miocene Mulinia 

congesta Conrad in their relative outlines and proportions, in their rather wide range of variation in general 

outline and dimensions, and in their ubiquitous 

abundance.

Occurrence: Oak Grove sand, localities 10659 P, 

3749 D . Shoal River formation, localities 3856 P, 5184r, 

5079 Dr, 10661°, 10662 p , 5193 r, 5194 r, 3733 P , 9957 P, 

10603°, 10608 P , ?5618r.

-50- fi (M2-K)
222 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Section MACTROMERIS Conrad

1868, January. Mactromeris Conrad, Am. Jour. Conchology 

for 1867, vol. 3, app., p. 45.

Type: Spisula ovalis Gould = Spisula polynyma 

(Stimpson). (Recent from Hudson Bay to Cape Ann, 

Mass.)

The section is characterized by the smooth laterals, 

the noncompressed cardinals, and the isolation of the 

anterior arm of the right cardinal from the ventral 

lamina.

Spisula (Hemimactra) dodona Dall

Plate XXXIII, Figures 13-15

1898. Spisula (Hemimactra) dodona Dall, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 4, p. 896, pi. 27, figs. 7, 13, 25.

Dall describes this species as follows:

Shell of moderate size, compressed, subtriangular, arcuate, 

nearly smooth or with fine incremental lines, subequilateral; 

the anterior side a trifle shorter, anterior slope impressed, 

slightly concave, anterior end rounded; base arcuate; posterior slope convex, mesially impressed, bounded by a slender, 

elevated line, with the intervening area minutely wrinkled; 

pallial sinus rounded, extending in front of the vertical of the 

beaks; hinge concentrated, the anterior arm of the right cardinal in line with the ventral lamina, both very short. Longitude 

50, altitude 34, diameter 15 millimeters.

This species is perhaps as near S. delumbis as any other, but 

is smaller and more compressed. The laminae are quite short 

and not striated.

Type: U. S. Nat. Mus. No. 135905.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The species is remarkable for the narrow and angular 

umbones. It is an exceedingly thin and fragile form 

and very rarely preserved in any degree of perfection. 

Like the Shoal River S, valhosierr, S. dodona is more 

closely allied to a Chesapeake Miocene species than 

it is to any described form from the Alum Bluff. The 

differences between S. dodona and S. delumbis Conrad the smaller, thinner, more compressed shell of 

the earlier species are similar to the differences that 

separate S. valhosierr from S. marylandica Dall but 

are much more marked.

Occurrence: Oak Grove sand, localities 2646 p, 

5630 r.

Spisula (Hemimactra) valhosierr Gardner, n. sp. 

Plate XXXIII, Figures 16-17

1898. Spisula (Hemimactra) marylandica Dall, Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 4, p. 897 (part; figure 

excluded).

Shell large, rather thick but fragile, ovate-trigonal in 

outline, inflated, medially compressed toward the 

margins. Umbones broadly arched, the tips acute 

and prosogyrate, slightly anterior. Lunule simulated 

by the large cordate depression in front of the umbones. 

Area behind the umbones also depressed, even narrowly concave. Posterior rostral area indicated by 

the texture rather than the contour of the shell.

Umbonal angle not far from 135°. Anterior slope a 

little steeper than the posterior. Anterior extremity 

broadly rounded. Posterior end of shell more produced than the anterior, obscurely truncate. Base 

line arcuate. External surface smooth except for 

incremental sculpture and the traces of the lineated 

epidermis, most distinct laterally; posterior area 

apparently sharply defined in the epidermis by faint 

but persistent radials and numerous interlacing 

threads. Hinge rather concentrated. Ligament 

mounted on a narrow wedge-shaped base close to the 

dorsal margin. Chondrophore large, deltoid, subumbonal, with a slight posterior inclination separated 

from the ligament area by a narrow, smooth space but 

no trace of a shell lamina. Right cardinal slender, 

the posterior arm usually broken away; anterior arm 

short, elevated, more nearly in line with the dorsal 

lamina than with the ventral; lateral grooves deep 

but rather short and close to the hinge, not striated; 

ventral laminae more elevated than the dorsal. Left 

cardinal small, prominently elevated above the hingeplate, acutely V-shaped, the anterior arm a little 

heavier and more produced than the posterior; lateral 

grooves not striated, deep, the inner margins elevated 

and laminar, clasped between the dorsal and ventral 

laminae of the opposite valve. Adductor scars large, 

rudely semielliptical in outline. Pallial line distinct 

but not conspicuous, the sinus elliptical, the dorsal 

margin nearly horizontal, produced, the rounded extremity in line with the umbones.

Dimensions: Altitude, 50± millimeters; latitude, 

75± millimeters; diameter, 27± millimeters.

Type: U. S. Nat. Mus. No. 351998.

Type locality: No. 3748, Somerville Mill Race, 

Walton County, Fla.

It is rather significant that Spisula valhosierr is 

much more closely affiliated with S. marylandica Dall 

and S. subponderosa D'Orbigny, of the Maryland 

Miocene, than with any of the Alum Bluff species. 

The southern species is more compressed than the 

northern, the umbones more evenly rounded, the 

anterior area less depressed, the posterior area less 

strongly indicated, and the anterior arm of the right 

cardinal more nearly in line with the dorsal lamina of 

the lateral.

Occurrence: Shoal River formation, localities 3856P, 

?3742r, 2238P, 3748P .

Genus MULINIA Gray

1837. Mulinia Gray, Mag. Nat. Hist., new ser., vol. 1, p. 375, 

London, Edward Gharlesworth.

Type: Mulinia iypicus Gray = Mactra edulis King. 

(Recent off Patagonia and in the Straits of Magellan.) 

Gray describes this genus as follows:

Shell ovate, trigonal, subangular at each end. Cardinal and 

lateral teeth like Mactra. Siphonal inflection ovate, distinct. 

Ligament internal in a triangular groove in the upper surface 

of the deep oblique cartilage pit quite hid from view.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 223

Mulinia represents among the Mactridae the final 

stage in the submersion of the ligament. In both the 

fossil and recent species, however, traces of the external 

ligament are often retained.

Mulinia orihria is the first of the genus to be reported 

from the east coast faunas in strata older than the 

Chesapeake Miocene. The Recent species are few in 

number but for the most part prolific in individuals, 

most of them denizens of the warm and temperate 

waters.

Mulinia orthria Gardner, n. sp.

Plate XXXIV, Figures 1-3

Shell small, very thin, high, rounded, trigonal, 

inflated, acutely rostrate and flattened posteriorly. 

Umbones subcentral, small, angulated laterally, the 

tips slightly incurved, the dorsal margins projecting 

beyond them. Lunule large, extending almost the 

entire length of the anterior dorsal margin, flattened, 

obscurely defined by a faintly incised line. Escutcheon relatively short, lanceolate, indicated by the 

abrupt disappearance of the incrementals. Anterior 

dorsal margin steeply declining, sharply rounded or 

obtusely angulated at its extremity. Posterior dorsal 

margin feebly arched, the posterior extremity obtusely 

truncate and rather sharply angulated at the terminus of the rostrum. Base line arcuate, quite 

strongly upcurved in front. External surface polished, 

smooth except for incrementals, least feeble behind 

the rostrum. Ligament internal, much reduced, 

almost obsolete. Resilium sunken, attached to a 

narrow chondrophore, deeply undercutting the umbones and overhung by the dorsal margin. Dentition 

extremely delicate, concentrated; anterior and posterior right cardinals very thin and laminar, not coalescent, set nearly at right angles to each other, the 

anterior parallel to the dorsal margin; left cardinals 

fused into an acute A, the anterior arm slightly more 

produced than the posterior; posterior accessory 

lamella exceedingly thin, proximate and parallel to 

the posterior arm; laterals short and close to the 

umbones, the double sockets in the right valve receiving the slender, elevated laminae of the left. 

Interior often corrugated concentrically and subject 

to irregularities of surface. Adductor scars distinct, 

the anterior relatively small and irregular in outline, 

the posterior rudely semielliptical. Pallial line distinct. Pallial sinus very short, the dorsal margin 

nearly horizontal, turning at an obtuse angle which 

often approaches 90° and joining the pallial line at 

an acute angle.

Dimensions: Right valve (cotype), altitude, 7.7 

millimeters; latitude, 9.6 millimeters; semidiameter, 

3.0 millimeters. Left valve (cotype), altitude, 9.0 

millimeters; latitude, 12.1 millimeters; semidiameter, 

4.0 millimeters.

Cotypes: U. S. Nat. Mus. No. 353935.

Type locality: No. 5618, 33/£ miles southwest of 

DeFuniak Springs, Walton County, Fla.

Mulinia orthria is of unusual interest because it is 

not only the sole representative of the genus in the 

Alum Bluff but the earliest Mulinia recognized in the 

east coast faunas. It is remarkable for the delicacy 

of the shell and dentition. In general characters it 

approaches more closely the Recent Mulinia lateralis 

subsp. corbuloides Deshayes than any of the Tertiary 

forms.

Occurrence: Shoal River formation, localities 9958C , 

3747P , 7264p , 5618P .

Family MESODESMATIDAE Deshayes

Dall 19 characterizes this family as follows:

This family, with a hinge formed on much the same plan as 

that of Mactra, is sharply distinguished from the latter by its 

separate, free, and naked retractile siphons, and also by a certain excessive solidity and thickness of its valves relatively 

to their comparative dimensions. It is by this latter habit 

of growth that the fossil species may be distinguished from 

the Mactras rather than by any clearly marked differential 

characters.

Subfamily ERVILINAE

Dall 20 gives the following description:

Shells small, thin, equilateral, concentrically sculptured or 

smooth; ligament marginal, obsolete, or absent; resilium small; 

hinge much concentrated; laterals small, dorsal anterior lamina 

absent, the ventral more or less coalescent with anterior arm of 

the right cardinal; left cardinal large, bifid; pallial sinus well 

marked.

This group has representatives in European seas, the West 

Indies and southeastern coast of North America, the Red Sea, 

and the Indo-Pacific region.

The right and the left cardinals have been transposed in the description.

Genus ERVILIA Turton

1822. Ervilia Turton, Conchylia insularum britannicarum: 

Dithyra, p. 55.

Type: Mya nitens Montagu. (Recent from the 

Tortugas to the northern coast of South America.)

Shell small, oval to triangular; umbones low, subcentral, slightly opisthogyrate; external ligament 

obsolete; internal, lodged in a small resilifer, situated 

between the anterior and posterior cardinals; lateral 

armature feeble; grooves developed in right valve; 

lateral teeth of left usually replaced by modifications 

of the dorsal margins; pallial sinus well defined.

These lentil-shaped bivalves form an inconspicuous 

factor in the marine faunas of the Tertiary and postTertiary seas. The recent forms are, for the most 

part, tropical.

i« Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 4, pp. 907-908, 1898. 

2° Idem, pp. 913-914.
224 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

This denizen of the warm seas is well represented at 

each of the Alum Bluff horizons. In number of individuals and ubiquitous distribution, Ervilia chipolana Dall is probably first, though at no locality does 

it form so prominent a factor in the fauna as E. valJiosierr near Shell Bluff, on Shoal River. The characteristic Chipola species persists in diminished numbers 

into the Oak Grove and possibly into the Shoal River. 

The characteristic Oak Grove form, however, is a very 

plain little shell suggesting that life in the cooler 

waters of the Oak Grove was more difficult than during the Chipola. Ervilia planata also may have 

persisted into the Shoal River, though apparently it 

left no descendants. The Shoal River species E. 

condra and E. valhosierr seem to be more closely 

related to E. chipolana than to the Oak Grove E. 

planata. Neither is very near to the more ovate forms 

of the later Tertiary faunas.

Valves not conspicuously flattened over the umbonal area; 

prodissoconch not remarkably prominent:

Concentric sculpture usually developed over the whole or a 

part of the surface; valves often inflated and obtusely 

rostrate posteriorly:

Shell often produced and attenuated posteriorly, 

relatively inflated and obtusely rostrate.

Ervilia chipolana Dall s. 1.

Shell relatively low, produced and attenuated

posteriorly---------Ervilia chipolana Dall s. s.

Shell relatively high, not produced and attenuated 

posteriorly.

Ervilia chipolana subsp. triangularis Dall. 

Shell not produced and attenuated posteriorly, relatively compressed and obscurely rostrate.

Ervilia condra Gardner, n. sp.

Sculpture reduced to incrementals and a microscopically 

fine concentric striation_l£m7ia valhosierr Gardner, n. sp. 

Valves conspicuously flattened over the umbonal area; prodissoconch remarkably prominent. ..-.-..Ervilia planata Dall.

Ervilia chipolana Dall 

Plate XXXIV, Figure 4

1898. Ervilia chipolana Dall, Wagner Free Inst. Sci. Trans., 

vol. 3, pt. 4, p. 914, pi. 33, fig. 10.

Dall describes this species as follows:

Shell small, inflated, pointed behind, the posterior part 

slightly longer, the anterior end shorter and rounder; the base 

evenly arched, the pallial sinus moderately wide, rounded in 

front, not reaching the vertical of the beaks; umbones low, not 

prominent; the sculpture of rather irregular concentric threads 

and grooves, absent from the umbones and frequently from a 

great part of the valves. Longitude 4.5, altitude 3, diameter 2 

millimeters.

This species, which is very common in the beds, is readily 

distinguished from E. concenlrica, to which it is most nearly 

allied, by its more pointed posterior end, its coarser and less 

regular sculpture, its less conspicuous beaks, and generally 

smaller size.

Type: U. S. Nat. Mus. No. 114603. 

Type locality: No. 2211, lower bed, Alum Bluff, 

Liberty County, Fla.

The high trigonal convex end members have been 

segregated under the subspecies triangularis Dall. 

Half a dozen other subspecies might be erected on the 

variations in outline and sculpture characters, but the 

intergrading is so close and uninterrupted that there is 

little to be gained by the multiplicity of names. There 

is not only a remarkable specific variation in sculpture, 

but the age variation as well is unusually wide. In 

some individuals the umbones are nearly smooth, 

with a later developed concentric sculpture; in others 

the early sculpture evanesces with maturity.

In the Oak Grove sand the species is much less 

common but more constant in its characters. The 

high trigonal subspecies has not been recognized and 

the great majority of the forms are produced and 

attenuated posteriorly and closely and regularly sculptured. A few juveniles from the Shoal River formation 

offer no characters by which they may be separated 

from E. chipolana. Ervilia condra, from the Shoal 

River, is a possible descendant. It runs smaller and 

usually higher than the Chipola form and develops a 

fine and regular umbonal sculpture which weakens or 

disappears rather abruptly about halfway to the base.

Occurrence: Chipola formation, localities 10609P , 

7893P, 7257P, 2213% 2564a, 3419a, 7151 C , 221 l c , 

7183P, 10660r ; Oak Grove sand, localities 2646P, 5632P, 

5630r, 5633r, 7054r, 9961 r ; Shoal River formation, 

locality ?5079r.

Ervilia chipolana subsp. triangularis Dall 

Plate XXXIV, Figure 5

1898. Ervilia triangularis Dall, Wagner Free Inst. Sci. Trans., 

vol. 3, pt. 4, p. 915, pi. 33, fig. 19.

Dall describes this species as follows:

Shell small, solid, plump, subtriangular, inequilateral, with 

steep nearly straight dorsal slopes and an evenly arched base; 

surface smooth or marked only by rather irregular incremental 

lines; pallial sinus rounded, falling a little short of the vertical 

from the beaks; umbones low, calyculate; hinge strong, with the 

cardinal teeth prominent, and the marginal grooves in the right 

valve to receive the dorsal edges of the opposite valve long and 

well marked. Longitude 5.5, altitude 4, diameter 2.5 millimeters.

This form may prove to be an extreme variety of E. chipolana, 

but the specimens so far collected are distinguished by their 

smoother surface, much more triangular form, and more inequilateral shell. It seems to be comparatively rare in the marl, and 

further study is required to settle its systematic value.

Type: U. S. Nat. Mus. No. 114704.

Type locality: No. 2213, 1 mile below Baileys Ferry, 

Chipola River, Calhoun County, Fla.

This group shares with other groups of the Mactracea a wide range of variation in outline and sculpture. 

Ervilia chipolana subsp. triangularis includes the relatively high and convex end members. The sculpture 

in both the species and subspecies is exceedingly variable, ranging from nearly smooth individuals to those 

developing a close and regular ornamentation.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 225

The subspecies is restricted apparently to the single 

horizon, though E. cJiipolana s. 1. occurs in the Oak 

Grove sand and possibly even in the Shoal River.

Occurrence: Chipola formation, locality 2213P.

Ervilia condra Gardner, n. sp.

Plate XXXIII, Figures 18-21

Shell small, rather solid, relatively high, trigonal in 

outline, moderately inflated in the umbonal region. 

Umbones subcentral, somewhat flattened upon their 

summits, the tips proximate and feebly opisthogyrate. 

Neither lunule nor escutcheon defined. Anterior 

dorsal margin a little higher than the posterior. 

Anterior extremity broadly rounded. Posterior extremity narrower, rounded or obscurely truncate. 

Base line arcuate. Prodissoconch preserved in many 

specimens, smooth, shining. Conch ornamented with 

an exceedingly variable concentric sculpture, usually 

fine, close, and regular in the young and adolescent 

shell and tending to become irregular and evanescent 

in the adult. External ligament obsolete. Internal 

ligament lodged in a minute triangular chondrophore 

sunk deep beneath the umbones. Dental armature 

heavy for so small a shell; anterior cardinal of right 

valve robust, cuneate; dorsal margin directly behind 

the umbone of the right valve, slightly elevated and 

modified to function as the posterior cardinal; anterior and posterior cardinals of left valve distinct but 

not prominent, partially fused with the dorsal margins; 

inner margin of chondrophore in left valve elevated and 

acute dorsal margins of right valve sulcated to receive 

the beveled edges of the corresponding valve. Interior 

slightly thickened over the area of the attached mantle. 

Adductor scars distinct, the anterior more elongated 

than the posterior. Pallial line distant from the base. 

Pallial sinus very broad, the dorsal margin nearly 

horizontal, produced almost to the median vertical.

Dimensions: Right valve (cotype), altitude, 2.5 

millimeters; latitude,3.3 millimeters; semidiameter, 1.2 

millimeters. Left valve (cotype), altitude, 3.1 millimeters; latitude, 4.3 millimeters; semidiameter, 1.25 

millimeters.

Cotypes: U. S. Nat. Mus. No. 352015.

Type locality: No. 3748, Somerville mill race, Walton County, Fla.

Ervilia condra Gardner, n. sp., seems to be little more 

than a sculptured E. valhosierr. Though smaller than 

the E. valhosierr from the type locality and perhaps a 

little higher, E. condra is very similar in general build 

and in the characters of the hinge. It is possibly the 

parent stock developed from E. chipolana, retaining 

the sculpture in the early stages of growth. In E, 

valhosierr, on the other hand, a species more closely 

identified with the Shoal River fauna, the concentric 

sculpture is undeveloped even in the earliest stages.

The three juveniles referred in early check lists to 

E. lata Dall probably belong to this species. E. lata

is more nearly ovate in outline than any of the Alum 

Bluff species and develops a rather sharp but often 

irregular sculpture, strongest toward the base.

Occurrence: Shoal River formation, localities ?2238r,

3748P.

Ervilia valhosierr Gardner, n. sp.

Plate XXXIV, Figures 6-9

Shell very small but solid, lustrous when fresh, 

feebly but evenly inflated, slightly produced and 

obscurely rostrate posteriorly. Umbones central or 

slightly anterior, low, somewhat flattened, proximate 

and feebly opisthogyrate. Lunule and escutcheon 

suggested by the marginal flattening of the shell but 

not defined. Dorsal margins diverging from the umbones at an angle of not far from 135°. Anterior 

extremity broadly rounded. Posterior extremity narrower, a little more produced and more sharply 

rounded. Base line quite strongly arcuate. Prodissoconch frequently preserved, smooth, shining and 

more highly inflated than the conch. External surface 

of conch smooth except for an incremental sculpture 

more or less regularly developed, a microscopically 

fine fortuitous concentric striation, and an occasional 

faint suggestion of radials. External ligament obsolete. Internal ligament lodged in a minute triangular 

chondrophore, the apex directly beneath the umbones. 

Dentition strong for so small a shell; anterior cardinal 

of right valve heavy, deltoid, not sulcate upon its 

upper surface; posterior right cardinal obsolete though 

the dorsal margin directly behind the umbone is 

slightly expanded and fits into a corresponding depression in the left valve; anterior cardinal of left 

valve well developed, produced, free from the dorsal 

margin; chondrophore separated from the trigonal 

socket that receives the anterior right cardinal by the 

raised and beveled inner margin of the chondrophore; 

posterior left cardinal obsolete; laterals feebly developed; a shallow sulcus running the entire extent of 

the anterior dorsal margin of the right valve and 

receiving the dorsal margin of the left; posterior 

dorsal margins very slightly modified. Interior often 

a little thickened over the surface of the attached 

mantle, a thickened vertical ray developed beneath 

the umbones of many individuals. Muscle scars distinct, slightly impressed; the posterior adductor semielliptical, the anterior more elongated; pedal scar 

small, distinctly impressed directly above the anterior 

adductor. Pallial line distant from the base. Pallial 

sinus short, broad, reaching almost or quite to the 

vertical dropped from the umbones.

Dimensions: Right valve (cotype), altitude, 4.2 

millimeters; latitude, 5.75 millimeters; semidiameter, 

1.55 millimeters. Left valve (cotype), altitude, 4.2 

millimeters; latitude, 5.8 millimeters; semidiameter, 

1.5 millimeters.

Cotypes: U. S. Nat. Mus. No. 352017.
226 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

Type locality: No. 5079, half a mile below Shell 

Bluff, Shoal River, Walton County, Fla.

Ervilia valhosierr shares with E. planata Dall an 

outer surface smooth except for incrementals. E. valhosierr is readily separable, however, by the higher and 

more inflated outline and the less prominent prodissoconch. The species is very abundant at the type 

locality and is the characteristic representative of the 

genus in the marl.

Occurrence: Shoal River formation, localities 5079pr; 

1066P, 10662P, 3733P , 3748C , 5618r, 10612r.

Ervilia planata Dall

Plate XXXIV, Figures 10-12

1898. Ervilia planata Dall, Wagner Free Inst. Sci. Trans., vol. 

3, pt. 4, p. 915.

Dall describes this species as follows:

Shell small, subtriangular, flattened, smooth or obscurely 

concentrically ridged, subequilateral; the beaks low, calyculate; 

the dorsal slopes slightly rounded, subequal; the base evenly 

arched, not projecting; hinge well developed, the marginal 

grooves in the right valve almost as long as the dorsal margins; 

pallial sinus small, rounded in front, falling considerably short 

of the vertical from the beaks. Longitude 3.25, altitude 2.25, 

diameter 1.5 millimeters.

This small form is distinctly flattened and looks not unlike 

the flat valve of some Corbulas. Only a few valves were obtained, but all agreed in this character. The sculpture seems 

to have been not unlike that of E. chipolana.

A single type was not selected, and I have not been 

able to identify the individual measured in the vial 

of worn and immature specimens labeled "Types." 

The specimens figured are from the same collection 

at the same locality. The measurements of the figured 

individuals are as follows: Right valve (paratype), 

altitude, 3.4 millimeters; latitude, 5.0 millimeters; 

semidiameter, 1.5 millimeters. Left valve (paratype), 

altitude, 3.4 millimeters; latitude, 4.9 millimeters: 

semidiameter, 1.5 millimeters.

Paratypes: U. S. Nat. Mus. No. 353936.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

These small shells are highly polished when fresh, and 

though flattened in the young and adolescent stages, 

the adults are as a rule, moderately inflated. The 

prodissoconch is preserved in many specimens as a 

minute but rather prominent and shining knob at the 

apex of the umbonal angle. The external surface is 

smooth except for an incremental sculpture best 

developed toward the margins and, on very fresh 

surfaces, a microscopically fine concentric striation. 

The resilifer is small, trigonal, and depressed beneath 

the umbones. The right anterior cardinal is relatively 

large and heavy and feebly sulcate upon its upper surface. The posterior cardinal is obsolete. The cardinals of the left valve are very much reduced and 

largely fused with the dorsal margins. The interior 

is thickened over the umbonal area of the adult.

The muscle scars are small but distinct and the 

pallial sinus usually produced in the adult as far as 

the vertical from the beaks.

Ervilia planata differs from both E. chipolana, and 

E. valhosierr in the less inflated shell, the greater flattening toward the umbones, and the more prominent 

prodissoconch. The less attenuated posterior extremity and the absence of any but an incremental sculpture are additional criteria in differentiating it from 

E. chipolana.

Ervilia planata Dall is remarkable for its solidity 

and the prominence of the minute prodissoconch.

The Shoal River individuals are all immature and 

doubtfully referable to this species.

Occurrence: Oak Grove sand, localities 2646C } 5632P, 

5631 r, 5633r, 7054r, 10659P, Shoal River formation, 

localities ?5079r, 3733 r.

Superfamily MYACEA 

Family CORBULIDAE Fleming 

Genus COEBUIA (Bruguiere) Lamarck 21

1798. Corbula Bruguiere, Tableau encyclop£dique etmethodique 

des trois regnes de la nature, vol. 1, pi. 230. (Figures 

only; no names.)

1799. Corbula Lamarck, Prodrome d'une nouvelle classification des coquilles: Soc. hist. nat. Paris Me"m., p. 89. 

(No species cited.)

1801. Corbula Lamarck, Systeme des animaux sans vertebres, 

p. 137.

Type: Corbula gibba (Olivi). (Recent off the west 

coast of Europe and in the Mediterranean; Tertiary 

of southern Europe.)

Bruguiere 22 in 1798 published a plate of 18 figures 

which he headed Corbula. He used no specific names, 

but his figures have been identified as follows:

la-c. Corbula sulcata Lamarck ( Corbula guineensis 

Muhlfeldt.)

2a-c. An indeterminate bivalve, probably a Chama.

3a-c. Corbula porcina Lamarck. Not identified with 

assurance. Possibly a varietal form of C. gibba 

(Olivi) from the Mediterranean; more probably an 

exotic; cf. C. acutangula Rissel, from the Red Sea. 2S

4a-d. Corbula nucleus Lamarck ( Corbula gibba (Olivi)). 

Recent on the west coast of Europe and in the Mediterranean. Tertiary of southern Europe.

5a c. Corbula gallica Lamarck. Eocene of the Paris Basin.

6a b. Corbula margaritacea Lamarck (=Anatina trapezoides 

Lamarck).

Lamarck determined most of the species on the 

original plate but cited no type. There is a reference 

to the plate in the Prodrome, 24 1799, but no species is 

mentioned. The first specific list which appeared in the 

Systeme,25 1801, included Corbula sulcata, C. laevigata,

« The following discussion has already appeared in similar but not identical form: 

Gardner, Julia, Xautilus, vol. 40, pp. 41-47, October, 1926.

22 Bruguiere, J. G., Tableau encyclopedique et methodique, vol. 1, pi. 230, Paris, 

1798.

ft Bucquoy, Eugene, Dautzenberg, Philippe, and Dollfus, G. F., Mollusques 

marins du Roussillon, vol. 2, pp. 582, 587, 1896.

2* Lamarck, J. B., Prodrome d'une nouvelle classification des coquilles: Soc. hist, 

nat. Paris Mem., p. 89, 1799.

25 Lamarck, J. B., SystCme des animaux sans vertebres, p. 137, 1801,
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 227

C. margaritacea, C. gallica, and C. striata. Corbula 

nucleus was added in 1818 in the Histoire naturelle. 26 

There is apparently no record of the selection of a 

type before the anonymous publication of "Lamarck's 

Genera of shells" in 1822. In this publication, which 

was later fixed upon Children, 27 Corbula nucleus 

Lamarck (= C. gibba (Olivi)) is definitely designated as 

the type of the genus.

This is at variance with the common usage and 

involves a realignment of the superspecific groups. 

The long synonymy of Corbula gibba testifies to its wide 

range and great variability. The type of the species, 

according to Bucquoy, Dautzenberg, and Dollfus, 

probably came from the Adriatic. The Mediterranean 

shells, as a rule, are not so large as those from the 

British waters. The species is characterized by the 

unequal, discrepantly sculptured valves; the right 

valve, is larger, relatively higher, and more trigonal in 

outline, obtusely rostrate posteriorly, concentrically 

rugose; the left valve smaller, transversely elongate, 

not rostrate posteriorly, with a sparse and irregular 

radial lineation and the concentric sculpture restricted 

largely to the ventral area. These are the characters 

which, at least in the east coast Tertiary and Recent 

faunas, have been commonly associated with Aloidis. 

Cossmann, Gray, and some of the other Europeans 

have included such forms under Agina Turton 28 and 

have cited, as the type of Agina, Mya inaequivalvis 

Montagu (= Corbula gibba (Olivi)). Agina, however, is 

monotypic and the type, Mya purpurea Montagu, is a 

Saxicava, probably S. arctica (Linnaeus), so that Agina 

falls into the synonymy of Saxicava rather than of 

Corbula.

Aloidis Mtihlfeldt 29 is also monotypic. The type, 

Corbula sulcata Lamarck, a Recent shell from the coast 

of Senegal (figs, la-c on Bruguiere's original plate), 

has been considered by Gray,30 Fischer,31 Cossmann,32 

Bucquoy, Dautzenberg, and Dollfus,33 Woodring,34 and 

others as the type of the genus Corbula. The species 

is not represented in the collections of the United 

States National Museum, but through the courtesy 

of the Academy of Natural Sciences, Philadelphia, the 

loan of good adult material has been obtained. The 

shell is large and coarse; the altitude of the right 

valve is 19 millimeters, the latitude, 25 millimeters; 

the altitude of the left valve, 15.5 millimeters, the 

latitude, 23 millimeters; the diameter of the double

26 Lamarck, J. B., Histoire naturelle des animaux sans vertebres, vol. 5, p. 496,1818. 

« Children, J. Q., Quart. Jour. Sci., vol. 14, p. 301, 1822.

28 Turton, William, Conchylia insularum Britannicarum, Dithyra, p. 54, 1822.

29 Miihlfeldt, Megerle von, Entwickelung eines neuen System der Schalthiergehause: Gesell. Naturf. Freunde Mag., 5. Jahr, p. 67, 1811. 

so Gray, J. E., Zool. Soc. London Proc., vol. 15, p. 191, 1847.

31 Fischer, Paul, Manuel de conchyliologie et de pateontologie conchyliologique, 

p. 1123, 1887.

32 Cossmann, M., Catalogue illustrt des coquilles fossiles de I'Eocene des environs 

de Paris, App. 5, p. 15,1913.

« Op. cit., p. 577.

34 Woodring, W. P., Contributions to the geology and paleontology of the West 

Indies, Miocene mollusks from Bowden, Jamaica: Carnegie Inst. Washington 

Pub. 366, p. 185,1925.

valves, 15.5 millimeters. The posterior keel is very 

sharp and defined posteriorly by a deep sulcus which 

persists from the nepionic shell to the margin. Both 

valves are coarsely rugose, the sculpture upon the 

right valve heavier than upon the left. Radial sculpture is absent upon the conch. The tips of the umbones are conspicuously capped by the nepionic 

valves, which differ from the adult valves to a remarkable degree. The prodissoconch valves are nearly 

equal, compressed, acutely rostrate posteriorly, and 

similarly sculptured with concentric rugae which 

strengthen toward the ventral margin. These are 

characters which suggest Cuneocorbula Dall rather 

than Aloidis. As a matter of fact, there are no east 

American shells sufficiently close to the large coarse 

Senegalese shell to suggest the representation of the 

C. sulcata group in east American waters in either 

Tertiary or Recent time. The species formerly referred to Aloidis by American conchologists are 

included under Corbula s. s.

Caestocorbula Vincent,35 type Corbula Jienckeliusi 

Nyst, is also a synonym of Corbula s. s. Caestocorbula 

was founded upon the supposed presence of a siphonal 

plate. The nature of the plate and the mode of 

attachment are not obvious from the description or 

the figure, but the plate is either quite foreign to the 

shell or a fortuitous character resulting possibly from 

some of the peculiar phenomena of breakage that the 

Corbulas occasionally show.

Cuneocorbula 56 was erected by Cossmann to include 

transversely elongated birostrate shells headed by 

Corbula biangulata Deshayes (Eocene of the Paris 

Basin) as the type of the subgenus. Corbula biangulata is a small, thin shell, much produced posteriorly, 

strongly bicarinate, feebly and irregularly sculptured and with little more than generic characters to 

ally it with the forms with which it has been commonly 

associated by most of the American conchologists. 

There seems to be no subgenus available to which 

the small, subequivalve, biconvex, transversely elongate, posteriorly rostrate, concentrically sculptured 

Corbulas, so common through the east coast and Gulf 

Tertiary deposits and in the Recent east American 

waters, may be referred. A new subgenus, Caryocorbula,37 has been proposed for the accommodation of 

this group.

Bicorbula Fischer 38 is monotypic, and the type is 

Corbula gallica Lamarck. Fischer accepted Corbula 

sulcata Lamarck as the type of the genus and established Bicorbula to include the large, subtrigonal, 

obtusely or not at all rostrate, and for the most part 

feebly sculptured shells. An obscure radial lineation 

is frequently developed on the right valve and is more

35 Vincent, E., Soc. roy. zool. et malacol. Belgique Annales, vol. 44, p. 141,1909.

36 Cossmann, M., op. cit., vol. 1, p. 37, 1886. 

3' Gardner, Julia, Nautilus, vol. 40, p. 46, October, 1926.

s8 Fischer, Paul, Manuel de conchyliologie et de palfiontologie conchyliologique, 

p. 1123, 1887.
228 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

obvious, as a rule, in the decorticated shell. Dall 

and others who considered Corbula gallica the type 

of Corbula s. s. could not, of course, recognize Bicorbula, but if Corbula gibba is accepted as the type of 

Corbula s. s. Bicorbula must be reinstated.

Bothrocorbula Gabb,39 characterized by the deep 

lunular pit beneath the beaks, retains its status unchanged. The monotype is Corbula viminea Guppy, 

from the Miocene (Bowden beds) of Jamaica.

Corbula s. 1., as here considered, has the following 

characteristics: Shell small, thick, ovate, more or 

less rostrate; valves unequal, the left usually smaller 

and flatter; umbones prominent, prosogyrate or 

erect, the right usually higher than the left; hinge 

line of right valve fitted with a single prominent tooth 

in front of the resilial pit; lateral laminae absent; 

left valve with a chondrophore and a deep cardinal 

socket; surface sculpture variable, commonly discrepant on the two valves of the same individual, 

usually concentric, never strongly radial; adductor 

scars distinct; pallial line indistinct; sinus feeble or 

obsolete.

A prominent genus among the small bivalves since 

the beginning of the Mesozoic. The recent Corbulas 

include some 70 species of almost universal distribution but more prolific in the warmer waters, particularly in the China seas.

The genus Corbula is one of the most numerous and 

most diversified in the Alum Bluff. Sixteen species 

and subspecies have been recognized, and others are 

indicated by fragments too imperfect to describe. The 

Chipola formation offers the most varied series. Each 

of its seven species is peculiar to the marl, though some

of them have near allies in the higher Alum Bluff beds. 

Five species from the Oak Grove have been described 

and five from the Shoal River, of which three are 

common to the two horizons. Corbula s. s. is abundantly represented by C. chipolana, a species intimately 

related to the later C. waltonensis and to C. heterogenea Guppy of the Bowden. The group of relatively 

large, transversely elongated Caryocorbulas reminiscent of the Vicksburg C. engonata and represented by 

C. sphenia, C. sarda, C. franci, and C. wakullensis is 

entirely restricted to the Chipola. The group C, whitfieldi Dall, on the other hand, possibly the precursor of 

the Recent (7. barrattiana, is characteristic of the Oak 

Grove and Shoal River, though it has a forerunner in 

C. whitfieldi boyntoni Gardner, found in the Chipola at 

Boynton Landing. The small, solid Caryocorbulas of 

the seminella type occur abundantly in the Chipola 

and Shoal River and are present in the Oak Grove. 

Caryocorbula JuniaTcensis is, apparently, a later offshoot of this group and has been found only in the 

uppermost beds of the Shoal River formation. The one 

Bicorbula occurs in the Chipola, though in a fragmentary state. Bothrocorbula is a remarkably compact 

and strikingly characterized group restricted to the 

middle and later Tertiary of Florida and the Antilles. 

It is represented in the Alum Bluff by a single not 

uncommon species in the Chipola and another closely 

allied and of similar occurrence in the Oak Grove, but 

it has not been detected in the Shoal River.

In Corbula, as in many other genera, the earlier 

Alum Bluff faunas, particularly the Chipola, are 

more obviously allied with the Antillean faunas than 

are those from the later horizons.

Valves conspicuously dissimilar in form and sculpture:

Altitude of adult rarely exceeding 6.0 millimeters. _______________________ ...Corbula chipolana (Dall MS.) Gardner, n. sp.

Altitude of adult commonly exceeding 6.0 millimeters-________________---_-_---------Cor£m/a waltonensis Gardner, n. sp.

Valves not conspicuously dissimilar in form and sculpture: 

Lunule not impressed:

Shell transversely elongated; latitude of adult exceeding 7.5 millimeters:

Latitude of adult exceeding 13.0 millimeters; surface sculpture coarse....-..-.Corbula (Caryocorbula) sphenia Dall.

Latitude of adult not exceeding 13.0 millimeters; surface sculpture fine, often irregular: 

Latitude of adult normally exceeding 9.0 millimeters:

Shell moderately inflated _________________________________________Cor?mZa (Caryocorbula) sarda Dall.

Shell much compressed. _________________________ .......Corbula (Caryocorbula) franci Gardner, n. sp.

Latitude of adult not exceeding 9.0 millimeters._ ...........Corbula (Caryocorbula) wakullensis Gardner, n. sp.

Shell relatively high; latitude of adult exceeding 7.5 millimeters-___----------_C'or&w/a (Caryocorbula) a?itoniae Maury.

Latitude of adult not exceeding 7.5 millimeters: 

Latitude of adult exceeding 6.0 millimeters: 

Shell relatively elongated transversely:

Radial beading little or not at all developed.________ .......--.Corbula (Caryocorbula) whitfieldi Dall s. s.

Radial beading developed over the whole or a part of the shell.

Corbula (Caryocorbula) whitfieldi stikta Gardner, n. subsp. 

Shell relatively high:

Concentric sculpture relatively fine and regular_Corbula (Caryocorbula) whitfieldi boyntoni Gardner, n. subsp.? 

Concentric sculpture rude and more or less irregular ...Corbula (Caryocorbula) parawhitfieldi Gardner, n. sp. 

Latitude of adult not exceeding 6.0 millimeters:

Radial lineation developed to a greater or less degree:

Shell compressed; concentric sculpture very irregular. ...Corbula (Caryocorbula) semenoides Gardner, n. sp.

Shell moderately inflated; concentric sculpture fairly regular______Corbula (Caryocorbula) seminella Dall.

Radial lineation not developed; shell conspicuously compressed- .Corbula (Caryocorbula) funiakensis Gardner, n. sp. 

Lunule impressed:

Shell relatively high____________________________________________________Cor?mZa (Bothrocorbula) synarmostes Dall.

Shell relatively elongated transversely--____-_______-_-_-__-_---__-----------Cor?mZa (Bothrocorbula) radiatula Dall.

« Gabb, W. M., Acad. Nat. Sci. Philadelphia Proc. for 1872, p. 274,1873.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 229

Subgenus CORBULA s. s.

1798. Corbula Bruguiere, Tableau encyclope"dique et me"thodique des trois regnes de la nature, vol. 1, pi. 230.

Aloidis of authors [not Aloidis Miihlfeldt, 1811]. 

Agina of authors, not Turton, .Conchylia insularum Britannicarum, Dithyra, p. 54, 1822. 

1909. Caestocorbula Vincent, Soc. roy. zool. et malacol. Belgique

Annales, vol. 44, p. 141.

Type: Corbula gibba (Olivi). (Recent on the west 

coast of Europe and in the Mediterranean; Tertiary 

of southern Europe.)

Shell rather small, inequivalve, inequilateral, discrepantly sculptured even in the juvenile stages; 

right valve larger, relatively higher and more trigonal 

in outline, obtusely rostrate posteriori}7 , concentrically 

rugose; left valve smaller, transversely elongate, not 

rostrate posteriorly, with a sparse and irregular radial 

lineation and a concentric sculpture restricted largely 

to the ventral area.

Corbula chipolana (Dall MS.) Gardner, n. sp. 

Plate XXXIV, Figures 13-17

1898. Corbula (Aloidis) heterogenea (Guppy MS.). Dall, 

Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 850 (part, 

figure excluded).

Shell small, solid, very strongly inequivalve; the 

margin of the left valve produced about 1 millimeter 

beyond that of the right but not recurved; the altitude of the left valve only about two-thirds that of 

the right. Umbones prominent, strongly rounded; 

that of the right valve much higher and more strongly 

incurved than that of the left; the tips acute, incurved, 

and prosogyrate, falling a little in front of the median 

vertical. Right valve rudely elevated, trigonal in 

exterior outline; the outline of the interior rudely 

quadrate; the umbones well above the gently sloping 

dorsal margins; anterior extremity smoothly rounded; 

posterior extremity squarely truncate; base line arcuate, anteriorly upcurved, subacutely angulated at the 

posterior basal margin; posterior keel subacute, with 

a less strongly defined secondary keel near the dorsal 

margin. Left valve ovate-trigonal in outline, smoothly 

rounded, with only a suggestion of a posterior keel; 

the anterior extremity and base arcuate; the posterior 

extremity obtusely truncate. Right and left valves 

differing as strongly in sculpture as in outline; umbones 

smooth and shining in both valves; right valve concentrically corrugated from near the umbones to the 

base, the rugae from 20 to 30 in number, becoming 

increasingly elevated toward the base and somewhat 

irregular, reduced upon the posterior area to growth 

wrinkles; sculpture of dorsal portion of left valve 

restricted to incrementals until the shell is nearly half 

grown; very fine radial lirae initiated away from the 

umbones, becoming slightly stronger toward the base, 

6 to 12 in number, absent upon the lateral areas but 

arranged with a fair degree of regularit3T over the disk.

Hinge characters rather delicate for so solid a shell. 

Ligament internal, attached to a small cuneate chondrophore projecting from the posterior dorsal margin 

and received in a deep subumbonal socket in the right 

valve. The single right cardinal moderately strong, 

conical, slightly recurved at the tip; socket beneath 

the left umbone correspondingly deep. Interior little 

or not at all thickened over the area of the attached 

mantle. Adductor scars small, obscure. Pallial sinus 

scarcely defined; pallial line usually obscure, simulated in the right valve by a well-defined groove which 

receives the edge of the left valve in the closed shell.

Dimensions: Double valves (cotj'pe, immature individual), altitude, 4.5 millimeters; latitude, 4.5 millimeters; diameter, 3.5 millimeters. Right valve (cotype), 

altitude, 5.75 millimeters; latitude, 6.5 millimeters; 

semidiameter, 4.1 millimeters. Left valve of a larger 

individual (cotype), altitude, 4.2 millimeters; latitude, 

5.75 millimeters; semidiameter, 2.1 millimeters.

Cotypes: U. S. Nat, Mus. No. 354021.

Type locality: No. 3419, McClelland farm, 1 mile 

below Baileys Ferry, Calhoun County, Fla.

The name chipolana was used by Dall upon the 

labels of the United States National Museum specimens, though the species was listed and discussed 

under the name heterogenea Guppy.

This, the earliest member of the group so widely 

distributed through the Floridian and West Indian 

provinces, runs smaller than any of its descendants. 

It is peculiar, too, in that both the concentric sculpture 

of the right valve and the radial sculpture of the left 

valve are usually initiated at a later stage of development than in any of the succeeding forms. The species 

is abundant and widespread in the Chipola but apparently did not survive the close of the epoch. The later 

waltonensis runs larger and relatively higher and more 

narrow.

Occurrence: Chipola formation, localities 10609P, 

7893P, 2212°, 7257P, 2213a , 2564a, 3419a, 7151 P, 

2211°, 7183P, 10660P .

Corbula waltonensis Gardner, n. sp. 

Plate XXXIV, Figures 18-21

Shell rather large for the group, moderately heavy, 

conspicuously inequivalve. Right valve high, narrow, 

rudely trigonal, strongly inflated, subacutely rostrate 

posteriorly, with a more obtuse secondary keel near 

the dorsal margin. Left valve transversely ovatetrigonal, moderately inflated, obscurely rostrate; the 

secondary keel indicated by a narrow groove, usually 

filled with callus, developed near the ventral margin. 

Umbo very much higher in the right valve than in the 

left, broad upon its summit, incurved; the tips of both 

valves prosogyrate and slightly anterior. Dorsal 

margins gently sloping, the anterior a little more 

steeply than the posterior. Anterior extremity strongly 

arcuate. Posterior extremity squarely truncate in the
232 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

The species is restricted in its known distribution 

to the type locality.

Occurrence: Chipola formation, locality 22IP.

Corbula (Caryocorbula) wakullensis Gardner, n. sp. 

Plate XXXV, Figures 5-6

Shell small, transversely elongated, the right valve 

slightly higher than the left, inequilateral, acutely 

rostrate posteriorly. Umbones moderately inflated, 

flattened upon their summits, the tips acute, proximate, and prosogyrate; umbonal angle not far from 

135°. Anterior extremity broadly and smoothly 

rounded. Posterior end attenuated, pinched and 

produced behind the rostrum, obliquely truncate. 

Base line feebly arcuate. Umbonal area smooth, 

except for feeble incrementals; medial and ventral 

portions of shell sculptured with about 15 concentric 

cords, fairly regular in size and spacing, evanescent 

near the anterior margin and directly in front of the 

rostrum; sculpture behind the rostrum incremental 

in character, strongest toward the ventral margin. 

Characters of ligament and hinge not known. Posterior adductor scar more prominent than the anterior. 

Pallial line entire, distinct.

Dimensions: Altitude, 4.8 millimeters; latitude, 9 

millimeters; semidiameter, 1.5 millimeters.

Type: U. S. Nat. Mus. No. 354024.

Type locality: No. 7468, Sopchoppy, Wakulla 

County, Fla.

Corbula wakullensis is much smaller and more 

finely sculptured than C. sarda Dall from Alum Bluff 

but similar in outline. The seedlike casts are very 

abundant at the type locality, but the available collections show no specimens from other localities.

Occurrence: Chipola formation, locality 7468a .

Corbula (Caryocorbula) antoniae Maury

1910. Corbula antoniae Maury, Bull. Am. Paleontology, vol. 4, 

No. 21, p. 34, pi. 9, fig. 1.

Maury describes this species as follows:

Shell very thick and solid, inflated, nearly equilateral, 

rounded in front, compressed and pointed behind so as to look 

as if pinched, and having a well-defined carina extending from 

the back to the posterior margin; beaks low; sculpture of rather 

unequal and not very regular concentric ribs which are absent 

from the region near the beaks.

Length of shell 10 millimeters; height 8 millimeters; diameter of inflated valve 6 millimeters.

Chipola marls, Baileys Ferry, Fla.

Cornell University collection.

The species has not been recognized in the available material.

Occurrence: Chipola formation, Cornell University 

collection.

Corbula (Caryocorbula) whitfieldi Dall 

Plate XXXV, Figure 7

1898. Corbula (Cuneocorbula) whitfieldi Dall, Wagner Free Inst.

Sci. Trans., vol. 3, pt. 4, p. 849. 

1900. Corbula (Cuneocorbula) whitfieldi Dall, idem, pt. 5,

p. 1192, pi. 36, fig. 18.

Dall describes this species as follows:

Shell small, solid, inflated, nearly equilateral, rounded in 

front, very obliquely truncate, and pointed behind, with a 

well-marked rostral carina and a slight emargination of the border of the valve below the rostrum; beaks low and inconspicuous; sculpture of rather coarse incremental lines and somewhat 

irregular concentric undulations, stronger in the middle of the 

shell, feeble on the beaks and with wider interspaces; base of 

the right valve folded upon the basal margin of the left valve. 

Longitude 7, altitude 4.5, diameter 3.4 millimeters. A small 

tubercle behind the socket and resilifer on the cardinal margin 

of the left valve.

This species is close to C. barrattiana C. B. Adams [see PL 

XXXVI, fig. 8], from which it differs by greater inflation and 

usually by the smaller number of concentric undulations and 

especially by the absence of any radial threads on the dorsal 

area of the rostrum. It recalls C. subcontracta Whitfield, 

which is a proportionately shorter shell and not as large.

Type: U. S. Nat. Mus. No. 135911.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Corbula whitfieldi is a more delicately formed and 

sculptured shell than its descendant parawliitfieldi. 

The earlier form, C. wJiitfieldi boyntoni Gardner, is 

smaller, relatively shorter and heavier, and, as a rule, 

more uniformly sculptured concentrically. The Oak 

Grove individuals that develop a radial sculpture have 

been isolated under the subspecies stikta. Corbula 

wJiitfieldi is the most abundant of the Oak Grove Corbulas and is common in the lower beds of the Shoal 

River.

Occurrence: Oak Grove sand, localities 2646a , 

5632a , 563P, 7054C , 9961°, 10659P, 3749r. Shoal River 

formation, localities 5079C , 1066P, 10662r, ?3733r.

Corbula (Caryocorbula) whitfieldi stikta Gardner, n. subsp. 

Plate XXXV, Figures 8-9

Shell small, flexuous, inequilateral, inequivalve, 

the right valve more strongly overlapping posteriorly 

than anteriorly. Umbones broadly rounded upon 

their summits, the tips incurved and prosogyrate, 

subcentral. Anterior end of shell strongly rounded. 

Posterior end bicarinate, broadly constricted in front 

of the subacute primary keel; secondary keel very 

close to the dorsal margin, acute in the left valve, 

obtuse in the right, the left posterior dorsal margin 

overlapped by the right almost to the keel; posterior 

extremity obliquely truncate. Base line flexuous in 

the right valve, nearly horizontal in the left. External surface concentrically wrinkled, the rugae 

feebler and more regular upon the right valve than 

the left, obsolete behind the primary keel; a microscopically fine and close radial beading developed in 

some individuals over the entire shell, in others upon 

the posterior area only. Ligament internal, seated 

upon a narrow chondrophore in the left valve, received in a subumbonal pit in the right. Right 

cardinal stout, tapering rapidly to the acute upcurved 

tip; cardinal socket in the left valve correspondingly 

wide and deep. Adductor scars distinct, the anterior
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 233

reniform, the posterior subcircular. Pallial line truncate posteriorly but not sinuate.

Dimensions: Double valves, altitude, 4.5 millimeters; latitude, 7.2 millimeters; diameter, 3 millimeters.

Type: U. S. Nat. Mus. No. 354026.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

The subspecies is characterized by the development of an exceedingly fine barrattiana-like threading. 

In some individuals the entire shell is covered except 

for the umbones and the area behind the secondary 

keel, but more commonly the radial sculpture is confined to the posterior half of the shell.

The distribution is similar in a general way to that 

of C. whitfieldi s.s., though much more restricted.

Occurrence: Oak Grove sand, localities 2646P, 

5632p .

Corbula (Caryocorbula) whitfieldi boyntoni Gardner, n. subsp.?

Plate XXXV, Figures 10-13

Shell small, solid, ovate-trigonal, inequilateral, 

inequivalve; the right valve a little larger than the 

left, more convex and somewhat flexuous. Umbones 

broadly rounded upon their summits, the tips proximate, acute, and piosogyrate, falling a little in front 

of the median vertical; umbonal angle not far from 

135°. Lunule not defined. Dorsal margins oblique, 

the anterior a little higher than the posterior. Anterior extremity broadly rounded. Posterior extremity obliquely truncate. Base line flexuous in the 

right valve, quite strongly arcuate medially, and 

broadly constricted in front of the posterior keel; 

base line in the left valve almost rectilinear. Posterior primary keel subacute; area obliquely flattened 

behind the keel; a secondary keel developed very 

close to the dorsal margin, obtuse in the right valve 

and acute in the left, the right dorsal margin in the 

closed valves overlapping the left to the secondary 

keel. External surface concentrically wrinkled, the 

rugae coarser upon the right valve than upon the left 

and coarser and less evenly spaced posteriorly than 

anteriorly; concentric sculpture behind the rostrum 

reduced to more or less laminar incrementals; microscopically fine radials fortuitously developed, most 

common behind the keel. Ligament internal, seated 

upon a short, laminar chondrophore in the right valve, 

received in the subumbonal socket of the left; a 

tubercle developed at the distal extremity of the 

chondrophore. Right cardinal strong, horizontally 

compressed, upcurved at the tip, received in a correspondingly wide and deep socket in the left valve. 

Adductor impressions distinct, the anterior reniform, 

the posterior subcircular. Pallial line running closer 

to the base posteriorly than anteriorly, slightly 

indented but with no well-defined sinus; line of 

closure in the right valve much more conspicuous

than the pallial line, running closer to the base anteriorly than posteriorly.

Dimensions: Right valve (cotype), altitude, 4 millimeters; latitude, 5.6 millimeters; semidiameter, 2.25 

millimeters. Left valve of another individual (cotype), 

altitude, 3.5 millimeters; latitude, 5.3 millimeters; 

semidiameter, 2 millimeters.

Cotypes: U. S. Nat. Mus. No. 354025.

Type locality: No. 7893, Boynton Landing, Choctawhatchee River, Washington County, Fla.

Corbula boyntoni is possibly nothing more than a 

short, solid, small subspecies of C. whitfieldi of the 

Oak Grove and Shoal River. It is very interesting to 

find this apparent precursor in the higher zone of the 

Chipola.

Occurrence: Chipola formation, localities 10609r, 

7893P, ?6175r.

Corbula (Caryocorbula) parawhitfieldi Gardner, n. sp. 

Plate XXXV, Figures 14-17

Shell rather small and heavy, inequilateral, inequivalve; the right valve more strongly overlapping the 

left posteriorly than anteriorly. Umbones low, broad, 

the right slightly higher than the left: the tips proximate and prosogyrate, subcentral. Lunule not defined. 

Posterior area bicarinate, the primary keel acute, the 

secondary very close to the dorsal margin and more 

sharply defined on the left valve than on the right; 

right posterior margin overlapping the left almost to 

the secondary keel. Anterior extremity of shell 

broadly and smoothly rounded. Posterior extremity 

obliquely truncate. Base line strongly arcuate in the 

right valve, slightly constricted behind the keel, 

nearly horizontal in the left valve. External surface 

concentrically corrugated, the wavelets usually sharper 

and less irregular in arrangement in the right valve 

than in the left, strengthening toward the base; 

secondary striae often developed toward the keel; 

both the primary and the secondary sculpture, abruptly 

disappearing at the keel; posterior area smooth except 

for incrementals, which are often somewhat laminar 

toward the base; faint traces of a fortuitous radial 

lineation occasionally visible posteriorly. Ligament 

internal, the laminar chondrophore produced from the 

posterior dorsal margin of the left valve, received in a 

deep subumbonal socket in the right; a small tubercle 

developed at the distal extremity of the chondrophore. 

Right cardinal somewhat compressed, upcurved and 

subacute at the tip, the cardinal socket of the left valve 

broadly trigonal. Adductor scars distinct; anterior adductor reniform, the posterior subcircular. Pallial line 

distinct, truncate posteriorly but not sinuate; line of 

closure of right valve strongly defined, running nearer 

to the base anteriorly than posteriorly.

Dimensions: Right valve (cotype), altitude, 4.8 

millimeters; latitude, 6.8 millimeters; semidiameter, 

2.55 millimeters. Left valve (cotype), altitude, 4.7
234 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

millimeters; latitude, 6.3 millimeters; semidiameter, 

2.5 millimeters.

Co types: U. S. Nat. Mus. No. 354027.

Type locality: No. 3856, 6 miles west-northwest of 

Mossyhead, Walton County, Fla.

Corbula parawhitfieldi is the close analog in the Shoal 

River of Corbula whitfieldi in the Oak Grove. The shell 

is higher relatively and ruder and has a more irregular 

sculpture. The species is common and widespread at 

the single horizon at which it occurs.

Occurrence: Shoal River formation, localities 3856C , 

3742 C , ?5079 r, 9958r, 3748P, 7264P, 9960r, 9957C , 

10603a, 10608pr, 5618P, 10612r.

Corbula (Caryocorbula) semenoides Gardner, n. sp. 

Plate XXXV, Figures 18-21

Shell minute but solid, moderately inflated, inequivalve; the margin of the larger, more convex right 

valve overlapping the left; the external outline rudely 

trigonal; the outline of the interior transversely ovatetrigonal. Umbones low, flattened upon their summits, 

prosogyrate, slightly anterior. Anterior end of shell 

strongly rounded. Posterior end produced along 

the rostrum, the lateral extremity obliquely truncate. Base line flexuous, constricted in front of the 

rostrum, arcuate anteriorly. Primary keel acute, 

the area behind it relatively wide; secondary keel 

directly in front of the dorsal margin. External 

sculpture incremental in character, absent upon the 

umbones and relatively heavy and crowded toward the 

base, not continued across the keel; concentric sculpture upon the posterior area reduced to fine incrementais; a minutely pustulose radial lineation developed 

upon fresh surfaces both upon the disk and behind the 

keel, crowded upon the posterior area and rather 

closely spaced upon the disk. Chondrophore short, 

relatively stout; a tubercle developed at the outer 

extremity; resilifer deep, undercutting the dorsal 

margin. Cardinal tooth in right valve short, horizontally compressed, upcurved at the tip; the cardinal 

socket of the left valve correspondingly wide and deep. 

Adductor scars relatively large; the anterior reniform; 

the posterior subcircular. Pallial line distant from the 

base; sinus a mere dent. Line of closure of left valve 

well defined upon the right, running closer to the 

margin anteriorly than posteriorly.

Dimensions: Right valve (cotype), altitude, 3.5 

millimeters; latitude, 4 millimeters; semidiameter, 1.5 

millimeters. Left valve of a larger individual (cotype), 

altitude, 3 millimeters; latitude, 4.5 millimeters; semidiameter, 1.3 millimeters.

Co types: U. S. Nat. Mus. No. 354028.

Type locality: No. 7151, Tenmile Creek, Calhoun 

County, Fla.

Corbula semenoides runs a little smaller than C. 

seminella Dall from the Oak Grove and Shoal River 

and is decidedly less inflated. The concentric sculpture is ruder than in the later form, and the radial 

sculpture is even finer and less constantly developed.

Corbula semenoides is the probable precursor of the 

more finely sculptured Corbula nucleata Dall, of the 

later Miocene and Pliocene of the southeast coast.

Occurrence: Chipola formation, localities 2212 P, 

7257 P, 2213 a, 2564% 3419 a, 7151 p .

Corbula (Caryocorbula) seminella Dall 

Plate XXXIV, Figure 24

1898. Corbula (Cuneocorbula) seminella Dall, Wagner Free Inst.

Sci. Trans., vol. 3, pt. 4, p. 848. 

1900. Corbula (Cuneocorbula) seminella DaU, idem, pt. 5,

p. 1192, pi. 36, fig. 11.

Dall describes this species as follows:

Shell small, inflated, compact, with low beaks a little anterior 

to the middle line, the left valve slightly smaller and enfolded 

below by the basal margin of the right valve, which has a 

flexuous edge; beaks nearly smooth, the valves below them with 

somewhat irregular, concentric undulations, and more or less 

faint radial striation; anterior end rounded, posterior end 

pointed, with a single strong rostral carina, below which the 

basal margin is a little ema'rginate. Longitude 4.5, altitude, 3, 

diameter 2 millimeters.

This is a very compact, solid, seedlike little shell, recalling 

C. aldrichi Meyer on a smaller scale.

Type: U. S. Nat. Mus. No. 135910.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Corbula seminella is apparently the descendant of 

the abundant Corbula semenoides of the Chipola. 

The later species is a little larger than the earlier and 

more inflated, with a more strongly overlapping right 

valve and a less faint and more persistent radial 

threading. The young of C. wJiitfieldi coexistent in 

the Oak Grove are thinner shelled and more elongated 

transversely, the concentric sculpture is coarser, and 

the radial lineation undeveloped.

Corbula seminella is much more abundant and more 

diversified in the Shoal River than at the horizon which 

furnished the type. The species attains greater 

dimensions in the Shoal River than it does in the Oak 

Grove, though the average individual is little larger 

than the type.

Occurrence: Oak Grove sand, localities 2646P, 

5632p, 5633r, 7054r, 9961°, 10659a , 3749P . Shoal River 

formation, localities 3856a , 3732r, 3742a, 10658P , 

5195r, 5079C , 10661 r , 9958P , 3748C , 3747P , 726P, 

7264P, 9960P, 9957r, 10603r, 5618C , 10612P .

Corbula (Caryocorbula) funiakensis Gardner, n. sp. 

Plate XXXV, Figures 22-25

Shell small, compressed, compact, inequivalve. 

Right valve slightly higher and less compressed than 

the left; the right posterior and ventral margins 

slightly overlapping those of the left, inequilateral, 

acutely rostrate posteriorly. Anterior dorsal margin 

more steeply declining than the posterior. Anterior
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 235

lateral margin smoothly rounded. Posterior extremity squarely truncate. Base line flexuous, particularly 

in the right valve, feebly constricted in front of the 

dorsal keel. Umbones low, flattened, the tips proximate and feebly prosogyrate, falling a little in front 

of the median vertical. Lunule and escutcheon not 

defined. Area behind the acute primary keel rather 

wide; secondary keel nearly obsolete in the left valve, 

fairly well defined and close to the dorsal margin in 

the right. Prodissoconch minute, smooth, shining, subcircular. External surface sculptured with feeble and 

irregular concentric waves, stronger in the left valve 

than in the right and initiated at an earlier growth 

stage, not persistent across the keel in either valve; 

sculpture upon the posterior area reduced to fine incremental striae and minute wrinkles; no trace of a radial sculpture detected. Ligament internal, mounted 

upon a slender lamina in the left valve, received in a 

subumbonal pit undercutting the dorsal margin; a 

small tubercle developed at the distal extremity of 

the nymph. Eight cardinal laterally compressed, 

wide but not conspicuously elevated, slightly recurved, 

received in the trigonal subumbonal pit of the left 

valve. Adductor scars deeply impressed, very close 

to the lateral margins; the anterior elongated, slightly 

reniform; the posterior subcircular. Pallial line distinct, running closer to the posterior margin than to 

the anterior, rising at almost a right angle to the 

posterior adductor but not sinuated; line of closure 

of the left valve very distinctly marked in the right.

Dimensions: Altitude, 3 millimeters; latitude, 4.3 

millimeters; diameter, 2.8 millimeters.

Type: U. S. Nat. Mus. No. 354029.

Type locality: No. 5618, 3J/-2 miles southwest of 

De Funiak Springs, Walton County, Fla.

Corbula junialcensis suggests a very compressed and 

feebly sculptured C. seminellci Ball. The slight 

dimensions, compressed valves, feeble concentric 

sculpture, and absence of any radial lineation readily 

isolate the species. It has been observed only in the 

upper zone of the Shoal River formation.

Occurrence: Shoal River formation, localities 3747P , 

7264p , 5618°.

Subgenus BICORBUIA Fischer

1887. Fischer, Manuel de conchyliologie et de palfiontologie 

conchyliologique, p. 1123.

Type: Corbula gallica Lamarck. (Eocene of the 

Paris Basin.)

Shell large, inequivalve; right valve larger and 

higher; left valve ovate-trigonal in outline; posterior 

keel obsolete or obscure on both valves; concentric 

sculpture feeble and irregular; a fortuitous radial lineation frequently developed on the left valve, most 

obvious on the decorticated shell; ligament pit profound; anterior cardinal prominent, the posterior not 

developed; an incipient pallial sinus usually developed.

Corbula (Bicorbula) sp. indet.

Two poorly preserved valves of a species apparently 

closely allied to C. idonea Conrad (see PL XXXV, 

figs. 26-28), of the Chesapeake group of Maryland, 

were collected at White Springs, on Suwannee River. 

They are much smaller than the Maryland individuals. 

Whether they represent a distinct species or are merely 

juvenile idonea can not be determined from the available material.

Occurrence: Chipola formation, locality 6769r.

Subgenus BOTHROCORBUIA Gabb

1873. Bothrocorbula Gabb, Acad. Nat. Sci. Philadelphia Proc. 

for 1872, p. 274.

Type: Bothrocorbula viminea Guppy. (Miocene of 

the Bowden beds of Jamaica.)

Shell moderately large and heavy, transversely 

ovate in outline, slightly inequivalve, acutely rostrate 

posteriorly; a coarse concentric corrugation and an 

inconstant radial striation developed on both valves; 

the deep lunular depression in front of the umbones 

the characteristic feature of the group; hinge heavy 

but otherwise normal.

Corbula (Bothrocorbula) synarmostes Dall

Plate XXXVI, Figures 1-2

1898. Corbula (Bothrocorbula) synarmostes Dall, Wagner Free

Inst. Sci. Trans., vol. 3, pt. 4, p. 850. 

1898. Corbula (C uneocorbula) engonata var. burnsii Dall, idem,

p. 847 (part). 

1900. Corbula (C uneocorbitla) synarmostes Dall, idem, pt. 5, p.

1192, pi. 36, figs. 12, 13.

Dall describes the species as follows:

Shell of moderate size, solid, ovate, pointed behind, nearly 

equilateral; beaks moderately elevated, small; anterior end 

rounded, base prominently arcuate; posterior end pointed, 

hardly rostrate, with a single rostral carina, below which the 

base is slightly emarginate; sculpture of strong, rounded undulations (about nine in number) not extending behind the carina, 

separated by about equal interspaces; sculpture feebler on the 

beaks; rostral area concentrically striated; lunular area slightly 

impressed but without any cellular excavation; surface, when 

perfect, with fine incremental lines and minute, irregularly 

distributed radial threads; cardinal tooth strong; a small 

tubercle on the hinge margin of the left valve behind the chondrophore; muscular scars deep; pallial line with a small sinus. 

Longitude 15, altitude 10, diameter 7.6 millimeters.

This species, though smaller, is externally very like the C. 

viminea, except that the lunular area is only slightly depressed, 

so that if attention were not particularly directed to it the 

depression might pass unnoticed, as it is not definitely limited.

Type: U. S. Nat. Mus. No. 154501.

Type locality: No. 2564, McClelland farm 1 mile 

below Baileys Ferry, Calhoun County, Fla.

The umbones are approximately central, but there 

is a marked discrepancy in the outline of the anterior 

and posterior ends of the shell. The posterior keel 

is sharply pinched at its extremity and slightly produced.
236 THE MOLLTJSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

The Chipola River individuals referred to C. 

engonata var. burnsii Dall are young and for the most 

part weathered C. synarmostes. The depression in 

front of the umbone is sufficient to separate the species 

from the members of other subgenera and from all 

other described species from the Chipola. The 

relatively high outline separates it from C. radiatula 

Dall, of the Oak Grove.

Occurrence: Chipola formation, localities 10609r, 

7893 P , 7257P, 2213°, 2564 P , 3419 P , 7151 P .

Corbula (Bothrocorbula) radiatula Dall 

Plate XXXVI, Figures 3-7

1898. Corbula (Bothrocorbula) radiatula Dall, Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 4, p. 851.

1898. PCorbula (Bothrocorbula) radiatula var. tenella Dall, 

idem, p. 851.

1900. Corbula (Bothrocorbula) radiatula Dall, idem, pt. 5, p. 

1192, pi. 36, figs. 1,2,3.

Dall, in 1898, described this species as follows:

Shell resembling the last species [Corbula synarmostes Dall], 

but smaller, less high in proportion, and longer, with the radiating threads more numerous and constant and the lunular area 

more deeply impressed, forming an elongated cellule with 

definite limits. Longitude 13, altitude 8.6, diameter 6.2 millimeters.

Variety tenella Dall; shell quite thin and delicate, the surface 

closely covered with minute radial threads.

This species has the lunular depression intermediate in 

depth between that of the last species [Corbula (Bothrocorbula) 

synarmostes Dall] and C. viminea.

Type: U. S. Nat. Mus. No. 107388; "var. tenella 

Dall," No. 135904.

Type locality: No. 2646, Oak Grove, Yellow River, 

Okaloosa County, Fla.

Corbula radiatula is the largest and heaviest of 

the Oak Grove Corbulas. The right valve is a little 

larger and more convex than the left, with a more 

strongly arcuate hinge. The umbones are somewhat 

flattened upon their summits, central or slightly anterior. The anterior extremity is strongly bowed, the 

posterior keel acute, produced, and attenuated ventrally. In front of the rostrum the base line is rather 

broadly constricted. The concentric undulations 

are very heavy and persist almost to the anterior 

dorsal margin, though they evanesce toward the umbones and a little in front of the keel. Behind the keel 

the sculpture is reduced to closely crowded laminae, 

incremental in character, laminar toward the base. 

The radials are exceedingly fine but sharply elevated 

lirae, absent upon the umbones and the posterior 

area and inclined to evanesce on the dorsal slope of 

the concentric ribs. The ligament is internal and 

is attached to a cuneate projection of the posterior 

dorsal margin of the left valve, which fits into a deep 

subumbonal socket directly behind the heavy conical 

tooth of the right valve. The cardinal socket of the 

left valve is correspondingly deep, the dorsal margins

sharply raised on either side, and a small tubercle 

developed at the ventral extremity of the chondrophore. The adductor scars and the scarcely sinuated 

pallial line are very distinct.

The status of the half dozen individuals from Oak 

Grove referred by Dall to the variety tenella can not 

be determined absolutely from the material available. 

They are probably specifically identical with Corbula 

radiatula Dall. The shell is not only conspicuously 

thin, but the base line is nearly horizontal from the 

rostrum to the anterior margin and markedly distinct 

from the convex anteriorly, concave posteriorly base 

of the normal adult radiatula. The concentric ribbing is similar in general characters to that of C. radiatula but more delicate. The microscopic radials are 

sharply beaded and in one individual crowd the posterior area. As in C. radiatula, however, they are 

absent upon the umbones. The characters of the interior suggest immaturity. It is obvious from a close 

observation of the adult C. radiatula that the attenuated rostrum, the constriction in front of the rostrum, 

and the overlapping ventral margin of the right valve 

with the consequent strongly arcuate outline are characters not acquired until the later adult stages. The 

sharpness of detail of the radial lirae also suggests 

immaturity. Apparently the animal did not begin to 

deposit on the inner surface until it had nearly completed its growth, so that we have the juvenile characters persisting through an unusually long period.

The type locality of Dall's var. tenella is the same 

as that of his radiatula, and the distribution, though 

more restricted, is similar.

Occurrence: Oak Grove sand, localities 2646°, 

5632P , 563lr, 5633r, 7054r. "Var. tenella," Oak Grove 

sand, localities 2646P , 5632P .

Family SPHENIOPSIDAE 

Genus SPHENIOPSIS Sandberger

1863. Spheniopsis Sandberger, Conchologie des Mainzer Tertiaer-Beckens, p. 289.

Type: Spheniopsis scalaris Brown. (Oligocene of 

the Mainzer beds of Germany.)

Except for the single Chipola species this genus is 

restricted in its known distribution to beds of the 

epoch from which it was first described, the Oligocene 

of Germany.

The shell is porcelaneous, small, compressed, equivalve, rudely trigonal, the posterior keel produced and 

the base line arcuate. The sculpture when developed 

is concentric. The ligament is internal and lodged in 

a deep subumbonal pit. There are two laminar teeth 

in the right valve, one on each side of the resilifer. 

The left valve is edentulous except for the marginal 

grooves which receive the cardinal lamellae of the 

right. The pallial sinus is rounded and moderately 

deep.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 237

The general characters of shell texture and outline, 

surface sculpture, and ligament attachment ally the 

genus, as suggested by Dall 40 in 1903, more closely 

with the Corbulidae than with any other family.

The dentition of SpJieniopsis, however, is far removed from that of the typical Corbulas too far, in 

the absence of peripheral forms, to permit their inclusion in the family group. Only the single species has 

been reported from the Western Hemisphere.

Spheniopsis americana Dall 

Plate XXXVI, Figures 9-10

1903. Spheniopsis americana Dall, Wagner Free Inst. Sci. 

Trans., vol. 3, pt. 6, p. 1508, pi. 57, figs. 28, 29.

Dall describes this species as follows:

Shell small, equivalve, rostrate; beaks small, pointed, subcentral; sculpture of a few, nearly concentric, relatively large 

waves, sometimes obsolete, and fine concentric striation; dorsal 

slopes steep, forming an angle of nearly 90° at the umbones; 

the anterior uud rounded, base arcuate, posterior end rostrate, 

slightly twisted, subtruncate terminally; hinge in the right 

valve of two diverging relatively strong lamellar teeth, between 

which is the resiliary pit and above which the margins are 

grooved to receive those of the opposite valve, which is edentulous; the fossette is subumbonal and not elevated; the muscular 

impressions are distinct, as is the pallial line, which has a short, 

wide, rounded sinus; the inner margins are entire. Length 3, 

height 2, diameter 1 millimeter.

The waves near the beaks are inconstant in strength and 

extent, but seldom cover more than a third of the disk.

Type: U. S. Nat. Mus. No. 114679.

Type locality: No. 2213, 1 mile below Baileys Ferry, 

Chipola Kiver, Calhoun County, Fla.

These small but exceedingly interesting forms are 

restricted in their known distribution to the environs 

of the type locality. There is no known species with 

which they can be confused, but, on the other hand, 

it is very difficult when first they are met to determine 

even their broadest alliances.

Occurrence: Chipola formation, localities 7257r, 

2213P , 7151 r.

Family SAXICAVIDAE Gray 

Genus PANOPE Menard de la Groye

1807. Panope Menard de la Groye, Memoire sur un nouveau 

genre de la famille des solenoides, p. 31.

Type: Panope aldro^andi Menard de la Groye. 

(Recent in the Mediterranean.)

Shell equivalve, oblong, gaping at both ends; surface smooth or concentrically furrowed; ligament 

external, conspicuous; a single prominent conical tooth 

in each valve; pallial sinus deep.

A genus that has been in existence since the end of 

the Cretaceous, culminated in the Tertiary, and is 

represented to-day by about a dozen species occurring 

chiefly in cooler waters.

Panope is represented at each of the three horizons 

of the Alum Bluff but at only one of them by material

10 Dall, W. n., Contributions to the Tertiary fauna of Florida: Wagner Free 

Inst. Sci. Trans., vol. 3, pt. 6, p. 1507, 1903.

sufficiently entire to describe. The Chipola and Shoal 

River forms are very similar and may be identical. 

Panope parawhitfieldi, from the cooler water deposits 

of the Oak Grove, is distinct and more closely allied 

to P. whitfieldi Dall, from the lower Chesapeake of the 

middle Atlantic slope.

Panope parawhitfieldi Gardner, n. sp. 

Plate XXXVI, Figures 11-12

1898. Panopea whitfieldi Dall, Wagner Free Inst. Sci. Trans.,

vol. 3, pt. 4, p. 829 (part). 

1915. Panope whitfieldi Dall, U. S. Nat. Mus. Bull. 90, p. 156,

pi. 18, figs. 1, 2 (part).

Shell large, thin, inflated, equivalve, inequilateral, 

more widely gaping posteriorly than anteriorly. 

Umbones slightly anterior, broad, rising above the 

dorsal margins, flattened upon their summits, the tips 

acute, incurved, and twisted slightly forward. Dorsal 

margins rectilinear, parallel to the base. Anterior 

extremity relatively short, broad, broadly rounded. 

Posterior extremity produced, slightly attenuated and 

expanded, strongly arcuate. Base line horizontal, 

more abruptly upcurved in front than behind. External surface rather strongly and evenly undulated concentrically in the umbonal region, the waves dying 

out away from the umbones and the sculpture reduced 

to incrementals rather sharply raised toward the dorsal margins. Surface microscopically pustulose, the 

pustules most crowded over the umbonal area and 

toward the posterior extremity, radially oriented 

near the posterior dorsal margin, frequently imbricated 

toward the lateral extremities. Nymphs heavy but 

rather short. A single slender, slightly upcurved, 

laterally compressed conical tooth in each valve. 

Interior somewhat thickened over the area of the 

attached mantle. Adductor scars relatively small, 

distinct, the anterior irregularly elongated, the posterior rudely reniform. Pallial line ragged, rather 

distant from the base; pallial sinus produced almost 

but not quite to the vertical dropped from the beaks.

Dimensions: Type, altitude, 48± millimeters; latitude, 90± millimeters; diameter, 33 millimeters. A 

less perfect individual attains an altitude of 60 

millimeters and a probable latitude of 110 millimeters.

Type: U. S. Nat. Mus. No. 135913..

Type locality: Oak Grove, Yellow River, Okaloosa 

County, Fla.

Panope whitfieldi Dall averages about 45 millimeters 

long by 83 millimeters wide in New Jersey and a little 

larger in Maryland but does not approach the size 

attained by some of the fragmentary individuals in 

Florida. The concentric sculpture upon the umbones 

is stronger and more regular in the southern species, 

and the pallial sinus in the few specimens observed is 

less profound.

The Chipola species is apparently distinct from the 

Oak Grove, differing in the more produced and attenuated posterior extremity. The material is too fragmentary to name.
238 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GROUP OF FLORIDA

The cast from Shoal River exhibits a similar 

outline.

The specimen figured in Bulletin 90 of the National Museum under the name whitfieldi is from 

Oak Grove and will serve as the type. The fragment 

from the "silex beds" lacks the strong sculpture that 

is characteristic of the Oak Grove race.

Occurrence: Oak Grove sand, localities 2646P , 5630r.

Panope sp. indet.

1898. Panopea whitfieldi Ball, Wagner Free Inst. Sci. Trans.,

vol. 3, pt. 4, p. 829 (part). 

1915. Panope whitfieldi Ball, U. S. Nat. Mus. Bull. 90, p. 156,

pi. 18, figs. 1, 2 (part).

The casts from the Chipola formation which have 

been referred to P. whitfieldi Dall apparently represent a race distinct at least subspecifically from both 

Panope whitfieldi Dall from the lower Chesapeake of 

the middle Atlantic coast, and Panope parawhitfieldi 

Gardner, n. sp., from the Oak Grove sand. The 

umbones are more decidedly anterior than in either of 

the other two species and the posterior extremity more 

attenuated. The umbonal sculpture lacks the strength 

and regularity which are shown by that of P. parawhitfieldi, and the sinus is produced to the vertical 

dropped from the beaks. The cast from the Shoal 

River formation is similar in outline to those from 

the Chipola.

Occurrence: Chipola formation, localities 2213P, 

?3419r, Shoal River formation, locality ?5184r.

Family GASTROCHAENIDAE Gray 

Genus GASTROCHAENA Spengler

1783. Nye Samling af det Kongelige Banske Videnskabers 

Selskabs Skrifter, vol. 2, p. 179.

Type: Gastrochaena cunei/ormis Spengler. (Recent 

in the West Indies.)

Shell inequilateral, thin, ovoid, or cuneiform, widely 

gaping ventrally and posteriorly; beaks low, anterior; 

ligament external; hinge edentulous; myophore developed for the support of the soft parts; adductor 

impressions unequal; pallial sinus deep, angular; bore 

cylindrical or flask-shaped, lined with calcareous 

matter.

Geologic range from the Mesozoic to the Recent. 

Geographic range, the warmer waters throughout the 

globe.

Two species have been recognized in the Alum 

Bluff Gastrochaena rotunda Dall, from the Chipola, 

and Gastrochaena dodona Gardner, n. sp., from the 

Oak Grove, the former identical with the species from 

the tropical fauna of the Bowden beds, the latter most 

closely allied to a more northern species from the

Chesapeake of Virginia. Additional evidence such as 

this for the cooling of waters at the end of Chipola 

time is always interesting.

Latitude approximately half the altitude; incremental sculpture 

almost obsolete medially ________-Gastrochaena rotunda Ball.

Latitude perceptibly less than half the altitude; incremental 

sculpture well developed medially.

Gastrochaena dodona Gardner, n. sp.

Gastrochaena rotunda Dall 

Plate XXXVI, Figure 13

1898. Gastrochaena ovata var. rotunda Ball, Wagner Free Inst. 

Sci. Trans., vol. 3, pt. 4, p. 825.

1915. Gastrochaena rotunda Ball, U. S. Nat. Mus. Bull. 90, p. 

157, pi. 19, fig. 2 (part).

1922. Gastrochaena rotunda Ball. Olsson, Bull. Am. Paleontology, vol. 9, No. 39, p. 438 (part).

1925. Gastrochaena (Gastrochaena} rotunda Ball. Woodring, 

Carnegie Inst. Washington Pub. 366, p. 192, pi. 26, 

figs. 11, 12.

Dall, in 1898, described this species as follows:

Shell resembling the ovata of the same size, but not attaining 

so large a size as the adult ovata, with a more rounded posterior 

end and rather shorter gape, the myophore decidedly larger, 

wider, and more conspicuous. Longitude 7, latitude 3.5, diameter 2.8 millimeters.

The differences between the recent and the Oligocene shells 

are so slight, and the range of variation in the living specimens 

so marked, that I feel unwilling, though the distinctive characters above mentioned seem constant, to give the fossil shells 

more than varietal rank until I have seen a larger number of 

specimens.

Type: U. S. Nat. Mus. No. 114705.

Type locality: 41 No. 2213, 1 mile below Baileys 

Ferry, Chipola River, Calhoun County, Fla.

The shell is very thin, ovate, and widely gaping 

posteriorly and ventrally, only partly covering the 

animal. The umbones are anterior and nearly terminal, the dorsal margin broadly arcuate, produced a 

little beyond the tips of the beaks and acutely angulated at the extremity. The posterior end is slightly 

expanded and evenly rounded, the ventral margin 

broadly constricted. The surface sculpture is incremental in character, the growth lines most elevated 

and most crowded ventrally, relatively distant along 

a cuneiform area extending from the umbones to the 

posterior margin, slightly more elevated and more 

closely spaced dorsally. The ligament is external and 

attached to slender nymphs extending about one-third 

the length of the dorsal margin. The hinge is edentulous, but there is a slender myophore springing from 

beneath the umbones. The inner margin is also rein41 The correctness of the locality label of the type has been questioned. Unfortunately, many of both the Chipola and the Bowden specimens show a reddish 

stain, and it is impossible to be sure from the appearance of the shell whether it was 

collected in Florida or in Jamaica.
TELLINACEA, SOLENACEA, MACTRACEA, MYACEA, MOLLUSCOIDEA 239

forced in the umbonal region by frail buttresses. The 

adductor scars are obscure and placed high up under 

the dorsal margin, the posterior irregular in outline 

and much larger than the anterior. The pallial sinus 

is produced almost or quite to the anterior third and 

is acutely angulated at its extremity.

Gastrochaena rotunda is a little smaller, relatively 

wider, and less strongly sculptured concentrically than 

the Oak Grove species.

The differences between the fossil and the recent 

species seem to be sufficiently constant to justify the 

raising of the Miocene form to specific rank.

A flask-shaped tube from the "silex beds" of the 

Tampa formation is assigned to this species, though 

there is little evidence of its identity with the shells 

described from Bowden and Chipola River.

Occurrence: Chipola formation, locality 2213 r.

Outside occurrence: Miocene: Silex beds? " of Tampa 

formation, Florida; Bowden beds, Jamaica.

Gastrochaena dodona Gardner, n. sp. 

Plate XXXVI, Figure 14

1898. Gastrochaena ligula H. C. Lea. Dall, Wagner Free Inst.

Sci. Trans., vol. 3, pt. 4, p. 825.

Not Gastrochaena ligula H. C. Lea, Am. Philos. Soc. 

Trans., vol. 9, p. 234, 1845.

Shell small, slender, mytiliform, thin, widely gaping 

posteriorly and ventrally, moderately inflated, flattened 

dorsally. Umbones low, inconspicuous, the tips obtuse 

and nearly terminal, the dorsal margin produced slightly 

beyond them and subacutely angulated at its extremity. Dorsal margin behind the umbones feebly 

arcuate. Posterior extremity rather sharply rounded. 

Ventral margin flexuous, broadly constricted medially. 

Incremental sculpture well developed over a cuneate 

area extending from the umbones to the posterior 

extremity, the incrementals following the outline of 

the margins, relatively crowded and elevated ventrally, inconspicuous though closely spaced dorsally. 

Ligament external, mounted on slender nymphs extending about one-third the length of the dorsal 

margin. Hinge edentulous. Myophore not preserved. 

Umbonal margin reinforced internally by feeble buttresses. Adductor impressions obscure, the posterior 

large, semielliptical, set high up under the dorsal 

margin. Pallial scars also obscure, the sinus apparently produced into the anterior third of the shell and 

obtusely angulated at its extremity.

Dimensions: Altitude, 6.2 millimeters; latitude, 2.7 

millimeters.

Type: U. S. Nat. Mus. No. 354030.

Type locality: No. 2646, Oak Grove, Yellow River., 

Okaloosa County, Fla.

Gastrochaena dodona Gardner, n. sp., is apparently 

consistently smaller than G. ligula (PL XXXVI, figs. 

15,16), from Petersburg, Va. It differs from the young 

of that species in the less flexuous ventral margin and 

the relatively wider dorsal flattening. Gastrochaena 

rotunda Dall, from the Chipola, is more expanded 

posteriorly, and in neither that species nor in the later 

Gastrochaena cuneijormis Spengler is the incremental 

sculpture so pronounced as that of G. dodona.

Gastrochaena dodona is restricted in its known distribution to the Oak Grove horizon.

Occurrence: Oak Grove sand, locality 2646P.

Phylum MOLLUSCOIDEA Huxley

Class BRACHIOPODA Cuvier

Order NEOTREMATA Beecher

Superfamily DISCINACEA Waagen

Family DISCINIDAE Gray

Genus DISCINISCA Dall

1871. Discinisca Dall, Am. Jour. Conchology, vol. 7, pt. 2, 

p. 74.

Type: Discina lamellosa Broderip. (Recent off 

Peru.)

Dall describes this genus as follows:

Lower valve more or less flattened, concave or compressed. 

Upper valve more convex; apexes of both subcentral or subposterior. Lower valve with a small septum as in Discina, behind 

which is an impressed disk or area, externally concave, and 

internally elevated. This is perforated by a longitudinal fissure, 

extending from a short distance behind the septum nearly to 

the posterior margin, which is often slightly indented behind it. 

Shell more or less horny in texture, minutely tubulous.

The discovery of a Discinisca allied to the Chesapeake lugubris in earlier and more southern deposits 

is of especial interest. The new species, Discinisca 

aldrichi, is apparently restricted to the youngest of 

the Alum Bluff beds.

Discinisca aldrichi Gardner, n. sp. 

Plate XXXVI, Figures 21, 22

Shell thin, fragile, laminar, phosphatic, dark brown. 

Ventral valve not known. Dorsal valve ovate-elliptical, asymmetrically convex, evenly declining from 

the obtuse apex which falls within the anterior fifth 

or sixth. Surface concentrically banded in varying 

shades of brown; sculpture reduced to incremental 

striae, the laminae discrete at the margin but not 

upon the apical surface; radials not developed. Adductor impressions distinct; anterior adductor scars 

large, somewhat reniform, a little more than onethird the altitude of the valve, their anterior extrem-
240 THE MOLLUSCAN FAUNA OF THE ALUM BLUFF GKOUP OF FLOKIDA

ities nearer one another than their posterior; posterior adductor scars small, rudely ovate, in line with 

the posterior extremities of the larger adductors.

Dimensions: Altitude, 9.5 millimeters; latitude, 

9.5 millimeters; diameter, 2.5 millimeters.

Type: U. S. Nat. Mus. No. 354031; collected and 

donated to U. S. National Museum by Truman H. 

Aldrich.

Type locality: Shoal River, Walton County, Fla.

Discinisca aldrichi is apparently the ancestor of 

Discinisca lugubris (see PL XXXVI, figs. 17-20) so 

characteristic of the Chesapeake Miocene. The 

valves of the earlier species run a little smaller and

thinner than those of the later and are less readily 

warped. The component concentric laminae are 

rarely visible except upon the margin, and radial 

sculpture is not developed.

I have the pleasure of dedicating this species to 

Truman H. Aldrich, a pioneer in the paleontologic 

work upon the southern Atlantic and Gulf Tertiary 

deposits. His collection, made and worked over 

during a life filled with business affairs, is one of the 

most remarkable in the country, and his persistent 

interest is an inspiration to those who are following.

Occurrence: Shoal River formation, Shoal River, 

Walton County, Fla.
PLATES XXIX-XXXVI

241
PLATE XXIX

[The specimen figured is the type unless otherwise stated. These type specimens have been remeasured, and some of the dimensions here given differ from those in the 

original descriptions]

Exterior of right valve (type); altitude, 23.0 millimeters; latitude, 38.0 

Exterior of right valve (type); altitude, 9.5 millimeters; latitude, 22.0

FIGURE 1. Tellina (Tellinella) chipolana Ball (p. 190).

millimeters. (After Dall.) 

FIGURE 2. Tellina (Tellinella) strophia Dall (p. 191).

millimeters. (After Dall.) 

FIGURES 3-5. Tettina (Tellinella) waltonensis Gardner, n. sp. (p. 191).

3. Exterior of right valve (cotype); altitude, 10.5 millimeters; latitude, 21.3 millimeters.

4. Interior of right valve (cotype); altitude, 10.5 millimeters; latitude, 21.3 millimeters.

5. Interior of left valve (cotype); altitude, 9.5 millimeters; latitude, 18.5 millimeters. 

FIGURE 6. Tellina [Arcopagia (Merisca)} aequistriata Say (p. 192). Exterior of left valve; altitude, 36.4 millimeters; latitude*

24.0 millimeters. (After Glenn.) 

FIGURES 7-11. Tellina [Arcopagia (Phyllodind)] dodona Dall (p. 192).

7. Exterior of left valve (cotype); altitude, 10.0 millimeters; latitude, 17.0 millimeters. (After Dall.)

8. Exterior of right valve (topotype); altitude, 17.0 millimeters; latitude, 27.0 millimeters.

9. Interior of right valve (topotype); altitude, 17.0 millimeters; latitude, 27.0 millimeters.

10. Interior of left valve (cotype); altitude, 20.5 millimeters; latitude, 33.5 millimeters.

11. Exterior of left valve (cotype); altitude, 20.5 millimeters; latitude, 33.5 millimeters. 

FIGURES 12-14. Tellina [Arcopagia (Phyllodina)} leptalea Gardner, n. sp. (p. 193).

12. Exterior of right valve (topotype); altitude, 10.0 millimeters; latitude, 17.0± millimeters.

13. Interior of left valve (type); altitude, 16.0 millimeters; latitude, 28.5 millimeters.

14. Exterior of left valve (type); altitude, 16.0 millimeters; latitude, 28.5 millimeters. 

FIGURE 15. Tellina [Arcopagia (Eurytettina)] roburina Dall (p. 194). Exterior of right valve (type);

latitude, 39.0 millimeters. (After Dall.) 

FIGURE 16. Tellina [Arcopagia (Eurytettina)] pressa Dall (p. 194).

latitude, 12.5 millimeters. (After Dall.) 

FIGURE 17. Tellina (Moerella) acosmita Dall (p. 196). Exterior of left valve (type); altitude, 5.0 millimeters; latitude, 10.5

millimeters. (After Dall.) 

242

altitude, 22.5 millimeters;

Exterior of right valve (type); altitude, 7.5 millimeters;
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXIX

10 11

TELLINACEA OF THE ALUM BLUFF GROUP
XI. S. GEOLOGICAL SURVEY PKOFESSIONAL PAPER 142 PLATE XXX

TELLINACEA OF THE ALUM BLUFF GROUP
PLATE XXX

FIGURES 1-2. Tellina (Moerella) doneta Dall (p. 195).

1. Exterior of left valve; altitude, 6.25 millimeters; latitude, 10.5 millimeters. (After Dall.)

2. Exterior of right valve (type); altitude, 8.5 millimeters; latitude, 13.5 millimeters. (After Dall.)

FIGURES. Tellina (Moerella) hypolispa Dall (p. 195). Exterior of left valve (type); altitude, 8.5 millimeters; latitude, 13.5 

millimeters. (After Dall.)

FIGURE 4. Tellina (Moerella) acloneta Dall (p. 196). Exterior of right valve (type); altitude, 3.0millimeters; latitude, 4.7 millimeters. 

(After Dall.)

FIGURE 5. Tellina (Moerella) agria Dall (p. 196). Exterior of left valve (type); altitude, 3.5 millimeters; latitude, 6.7 millimeters. 

(After Dall.)

FIGURE 6. Tellina (Moerella) ctenota Gardner, n. sp. (p. 197). Exterior of right valve (type); altitude, 5.2 millimeters; latitude 

9.0 millimeters.

FIGURE 7. Tellina (Moerella) acalypta Dall (p. 197). Exterior of right valve (type); altitude, 5.5 millimeters; latitude, 10.5 millimeters. (After Dall.)

FIGURES 8-10. Tellina (Moerella) piesa Gardner, n. sp. (p. 197).

8. Umbonal view of double valves; latitude, 11.0 millimeters; diameter, 3.0 millimeters.

9. Interior of left valve (type); altitude, 5.2 millimeters; latitude, 9.5 millimeters. 

10. Exterior of left valve (type); altitude, 5.2 millimeters; latitude, 9.5 millimeters. 

FIGURE 11. Tellina [Arcopagia (Scissula)] lampra Dall (p. 194). Exterior of right valve (type); altitude, 9.5 millimeters; latitude,

17.0± millimeters. (After Dall.) 

FIGURES 12-13. Strigilla georgiana Gardner, n. sp. (p. 199).

12. Interior of left valve (type); altitude, 9.8 millimeters; latitude, 11.0 millimeters.

13. Exterior of left valve (type); altitude, 9.8 millimeters; latitude, 11.0 millimeters. 

FIGURES 14-15. Strigilla paraflexuosa Gardner, n. sp. (p. 199).

14. Exterior of right valve (cotype); altitude, 7.2 millimeters; latitude, 7.8 millimeters.

15. Detail of sculpture of left valve (cotype); altitude, 6.3 millimeters; semidiameter, 2.0 millimeters. 

FIGURES 16-18. Strigilla sphaerion Gardner, n. sp. (p. 200).

16. Interior of left valve (cotype); altitude, 11.0 millimeters; latitude, 11.6 millimeters.

17. Exterior of right valve (cotype); altitude, 9.8 millimeters; latitude, 10.1 millimeters.

18. Detail of sculpture of right valve (cotype); altitude, 6.7 millimeters; latitude, 7.0 millimeters. 

FIGURE 19. Metis chipolana Dall (p. 200). Exterior of left valve (type); altitude, 36.0 millimeters; latitude, 44.5 millimeters.

(After Dall.) 

FIGURES 20-21. Macoma paralenis Gardner, n. sp. (p. 201).

20. Interior of right valve (type); altitude, 26.3 millimeters; latitude, 41.5 millimeters.

21. Exterior of right valve (type); altitude, 26.3 millimeters; latitude, 41.5 millimeters.

243
PLATE XXXI

FIGURE 1. Macoma (Psammacoma) tracta Dall (p. 202). Exterior of right valve (type); altitude, 5.0 millimeters; latitude, 12.7

millimeters. (After Dall.) 

FIGURES 2-4. Macoma (Psammacoma) torynoides Gardner, n. sp. (p. 202).

2. Exterior of right valve (type); altitude, 6.3 millimeters; latitude, 12.5 millimeters.

3. Interior of right valve (type); altitude, 6.3 millimeters; latitude, 12.5 millimeters.

4. Exterior of left valve (paratype); altitude, 5.4 millimeters; latitude, 11.5 millimeters. 

FIGURES 5-6. Macoma (Psammacoma) marmorea Gardner, n. sp. (p. 202).

5. Exterior of left valve (type); altitude, 6.6 millimeters; latitude, 14.5 millimeters. 

G. Interior of left valve (type); altitude, 6.6 millimeters; latitude, 14.5 millimeters. 

FIGURE 7. Semele chipolana Dall (p. 204). Exterior of right valve (type); altitude, 46.0 millimeters; latitude, 54.0 millimeters.

(After Dall.) 

FIGURE 8. Semele smithii Dall (p. 204). Exterior of right valve (type); altitude, 19.0± millimeters; latitude, 23.0 millimeters.

(After Dall.) 

FIGURE 9. Semele mutica Dall (p. 204). Exterior of right valve (type); altitude, 6.9 millimeters; latitude, 10.0 millimeters. (After

Dall.) 

FIGURE 10. Semele stearnsii Dall (p. 205). Exterior of right valve (type); altitude, 8.0 millimeters; latitude, 11.5 millimeters.

(After Dall.) 

FIGURE 11. Semele scintillata Dall (p. 205). Exterior of right valve (type); altitude, 6.7 millimeters; latitude, 9.5 millimeters.

(After Dall.) 

FIGURES 12-13. Semele compacta Dall (p. 205).

12. Exterior of right valve (type); altitude, 12.2 millimeters; latitude, 16.7 millimeters. (After Dall.)

13. Interior of right valve (type); altitude, 12.2 millimeters; latitude, 16.7 millimeters. (After Dall.) 

FIGURES 14-15. Semele taracodes Gardner, n. sp. (p. 206).

14. Interior of right valve (type); altitude, 12.1 millimeters; latitude, 16.5 millimeters.

15. Exterior of right valve (type); altitude, 12.1 millimeters; latitude, 16.5 millimeters. 

FIGURES 16-17. Semele paramutica Gardner, n. sp. (p. 207).

16. Interior of left valve (paratype); altitude, 11.4 millimeters; latitude, 14.5 millimeters.

17. Exterior of right valve (type); altitude, 10.5 millimeters; latitude, 14.5 millimeters. 

FIGURES 18-19. Semele sellardsi Gardner, n. sp. (p. 207).

18. Interior of left valve (type); altitude, 11.0 millimeters; latitude, 14.5 millimeters.

19. Exterior of left valve (type); altitude, 11.0 millimeters; latitude, 14.5 millimeters. 

244
tJ. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXXI

TELLINACEA OF THE ALUM BLUFF GROUP
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXXII

TELLINACEA OF THE ALUM BLUFF GROUP
PLATE XXXII

FIGURES 1-5. Semele (Semelind) cytheroidea Dall (p. 208).

1. Exterior of left valve (cotype); altitude, 3.5 millimeters; latitude, 4.75 millimeters. (After Dall.)

2. Interior of right valve (eotype); altitude, 3.75 millimeters; latitude, 5.0 millimeters.

3. Exterior of right valve (cotype); altitude, 3.75 millimeters; latitude, 5.0 millimeters.

4. Interior of left valve (paratype); altitude, 3.5 millimeters; latitude, 4.5 millimeters.

5. Exterior of left valve (paratype); altitude, 3.5 millimeters; latitude, 4.5 millimeters. 

FIGURES 6-8. Semele (Semelind) striulata Dall (p. 209).

6. Interior of right valve (eotype); altitude, 3.3 millimeters; latitude, 4.5 millimeters.

7. Interior of left valve (cotype); altitude, 3.0 millimeters; latitude, 4.2 millimeters.

8. Exterior of left valve (cotype); altitude, 3.0 millimeters; latitude, 4.2 millimeters. 

FIGURES 9-10. Abra cylicion Gardner, n. sp. (p. 209).

9. Interior of right valve (type); altitude, 7.5 millimeters; latitude, 10.0 millimeters.

10. Exterior of right valve (type); altitude, 7-5 millimeters; latitude, 10.0 millimeters. 

FIGURES 11-13. Abra lapochi Gardner, n. sp. (p. 210).

11. Exterior of right valve (cotype); altitude, 6.7 millimeters; latitude, 9.5 millimeters.

12. Interior of right valve (cotype); altitude, 6.7 millimeters; latitude, 9.5 millimeters.

13. Exterior of left valve (cotype); altitude, 6.9 millimeters; latitude, 10.5 millimeters. 

FIGURES 14-15. Donax (Paradonax) aldrichi Gardner, n. sp. (p. 212).

14. Interior of left valve (type); altitude, 7.5 millimeters; latitude, 15.8 millimeters.

15. Exterior of left valve (type); altitude, 7.5 millimeters; latitude, 15.8 millimeters. 

FIGURES 16-17. Donax (Paradonax) valhosierr Gardner, n. sp. (p. 213).

16. Exterior of right valve (type); altitude, 7.0 millimeters; latitude, 12.0± millimeters.

17. Interior of right valve (type); altitude, 7.0 millimeters; latitude, 12.0± millimeters. 

FIGURE 18. Donax chipolanus Dall (p. 211). Interior of right valve (type); altitude, 5.5 millimeters; latitude, 9.5 millimeters.

(After Dall.) 

FIGURE 19. Donax chipolanus subsp.? curtulus Dall (p. 211). Exterior of left valve (type); altitude, 3.5 millimeters; latitude,

5.5 millimeters. 

FIGURES 20-22. Donax trueloides Gardner, n. sp. (p. 212).

20. Interior of right valve (type); altitude, 9.5 millimeters; latitude, 12.2 millimeters.

21. Exterior of right valve (type); altitude, 9.5 millimeters; latitude, 12.2 millimeters.

22. Interior of left valve (paratype); altitude, 7.0 millimeters; latitude, 10.2 millimeters. 

FIGURES 23-26. Psammobia bowdichi Gardner, n. sp. (p. 214).

23. Hinge of right valve.

24. Umbonal area of left valve.

25. Interior of left valve (type); altitude, 11.5 millimeters; latitude, 19.5 millimeters.

26. Exterior of left valve (type); altitude, 11.5 millimeters; latitude, 19.5 millimeters. 

FIGURE 27. Tagelus sp. cf. Tagelus divisus (Spengler) (p. 215). Interior of right valve; altitude, 11.0 millimeters; latitude, 30.5

millimeters.

FIGURE 28. Semele paramutica Gardner, n. sp. (p. 207). Interior of right valve (type); altitude, 10.5 millimeters; latitude, 14.5 

millimeters.

245
PLATE XXXIII

FIGURE 1. Psamosolen vicksburgensis Aldrich (p. 216). Exterior of left valve (type, Johns Hopkins University collections); altitude, 13.5 millimeters; latitude, 29.0± millimeters. 

FIGURES 2-3. Psamosolen aldrichi Gardner, n. sp. (p. 216).

2. Exterior of right valve (type); altitude, 15.0± millimeters; latitude, 35.0± millimeters.

3. Hinge of right valve. 

FIGURE 4. Solen amphistemma Ball (p. 217). Interior of right valve (type); altitude, 27.5 millimeters; latitude, 112.0 millimeters.

(After Ball.) 

FIGURES 5-6. Ensis directus (Conrad) (p. 218).

5. Exterior of right valve; altitude, 12.0 millimeters; latitude, 102.0 millimeters. (After Glenn.)

6. Interior of left valve; altitude, 12.0 millimeters; latitude, 98.5 millimeters.

FIGURE 7. Mactra chipolana Ball (p. 219). Hinge of left valve (type). (After Ball.)

FIGURE 8. Mactra (Mactrotoma) cymata Ball (p. 220). Exterior of right valve (type); altitude, 20.0 millimeters; latitude, 31.5 

millimeters. (After Ball.)

FIGURE 9. Spisula (Hemimactra) densa Ball (p. 221). Exterior of left valve (type); altitude, 9.5 millimeters; latitude, 13.5 millimeters. (After Ball.)

FIGURES 10-12. Spisula (Hemimactra) craspedota Gardner, n. sp. (p. 221).

10. Exterior of left valve (cotype); altitude, 9.9 millimeters; latitude, 14.1 millimeters.

11. Interior of left valve (cotype); altitude, 9.9 millimeters; latitude, 14.1 millimeters.

12. Interior of right valve (cotype); altitude, 10.4 millimeters; latitude, 15.3 millimeters. 

FIGURES 13 15. Spisula (Hemimactra) dodona Ball (p. 222).

13. Exterior of right valve (type); altitude, 34.0 millimeters; latitude, 50.0 millimeters. (After Ball.)

14. Hinge of right valve (paratype). (After Ball.)

15. Hinge of left valve (paratype). (After Ball.) 

FIGURES 16-17. Spisula (Hemimactra) valhosierr Gardner, n. sp. (p. 222).

16. Interior of right valve (type); altitude, 50.0± millimeters; latitude, 75.0± millimeters.

17. Exterior of left valve (type); altitude, 50.0± millimeters; latitude, 75.0± millimeters. 

FIGURES 18-21. Ervilia condra Gardner, n. sp. (p. 225).

18. Exterior of left valve (cotype); altitude, 3.1 millimeters; latitude, 4.3 millimeters.

19. Exterior of right valve (cotype); altitude, 2.5 millimeters; latitude, 3.3 millimeters.

20. Interior of right valve (cotype); altitude, 2.5 millimeters; latitude, 3.3 millimeters.

21. Interior of left valve (cotype); altitude, 3.1 millimeters; latitude, 4.3 millimeters. 

246
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXXIII

17

TELIJNACEA, SOLENACEA, AND MACTHACEA OF THE ALUM BLUFF GROUP
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXXIV

20 21

MACTRACEA AND MYACEA OF THE ALUM BLUFF GROUP

18
PLATE XXXIV

FIGURES 1-3. MuJ/inia orthria Gardner, n. sp. (p. 223).

1. Interior of left valve (cotype); altitude, 9.0 millimeters; latitude, 12.1 millimeters.

2. Exterior of left valve (cotype); altitude, 9.0 millimeters; latitude, 12.1 millimeters.

3. Interior of right valve (cotype); altitude, 7.7 millimeters; latitude, 9.6 millimeters. 

FIGURE 4. Ervilia chipolana Dall (p. 224). Exterior of right valve (type); altitude, 3.0 millimeters; latitude, 4.5 millimeters.

(After Dall.) 

FIGURE 5. Ervilia chipolana subsp. triangularis Dall (p. 224). Exterior of left valve (type); altitude, 4.0 millimeters; latitude,

5.5 millimeters. (After Dall.) 

FIGURES 6-9. Ervilia valhosierr Gardner, n. sp. (p. 225).

6. Exterior of left valve (cotype); altitude, 4.2 millimeters; latitude, 5.8 millimeters.

7. Interior of left valve (cotype); altitude, 4.2 millimeters; latitude, 5.8 millimeters.

8. Exterior of right valve (cotype); altitude, 4.2 millimeters; latitude, 5.75 millimeters.

9. Interior of right valve (cotype); altitude, 4.2 millimeters; latitude, 5.75 millimeters. 

FIGURES 10-12. Ervilia planata Dall (p. 226).

10. Exterior of left valve (paratype); altitude, 3.4 millimeters; latitude, 4.9 millimeters.

11. Exterior of right valve (paratype); altitude, 3.4 millimeters; latitude, 5.0 millimeters.

12. Interior of right valve (paratype); altitude, 3.4 millimeters; latitude, 5.0 millimeters. 

FIGURES 13-17. Corbula chipolana Gardner, n. sp. (p. 229).

13. Double valves (cotype); altitude, 4.5 millimeters; latitude, 4.5 millimeters.

14. Exterior of right valve (cotype); altitude, 5.75 millimeters; latitude, 6.5 millimeters.

15. Interior of right valve (cotype); altitude, 5.75 millimeters; latitude, 6.5 millimeters.

16. Interior of left valve (cotype); altitude, 4.2 millimeters; latitude, 5.75 millimeters.

17. Exterior of left valve (cotype); altitude, 4.2 millimeters; latitude, 5.75 millimeters. 

FIGURES 18-21. Corbula waltonensis Gardner, n. sp. (p. 229).

18. Exterior of right valve (cotype); altitude, 7.0 millimeters; latitude, 7.5 millimeters.

19. Interior of right valve (cotype); altitude, 7.0 millimeters; latitude, 7.5 millimeters.

20. Interior of left valve (cotype); altitude, 5.4 millimeters; latitude, 6.5 millimeters.

21. Exterior of left valve (cotype); altitude, 5.4 millimeters; latitude, 6.5 millimeters. 

FIGURE 22. Corbula (Caryocorbula) sphenia Dall (p. 230). Exterior of right valve (type); altitude, 10.0 millimeters; latitude,

17.0 millimeters. (After Dall). 

FIGURE 23. Corbula (Caryocorbula) sarda Dall (p. 231). Exterior of right valve (type); altitude, 7.0 millimeters; latitude, 12.0

millimeters. (After Dall.)

FIGURE 24. Corbula (Caryocorbula) seminella Dall (p. 234). Double valves (type); altitude, 3.0 millimeters; latitude, 4.5 millimeters. (After Dall.)

247
PLATE XXXV

FIGURES 1-4. Corbula (Caryocorbula) franci Gardner, n. sp. (p. 231).

1. Exterior of right valve (cotype); altitude, 5.6 millimeters; latitude, 8.8 millimeters.

2. Interior of right valve (cotype); altitude, 5.6 millimeters; latitude, 8.8 millimeters.

3. Exterior of left valve (cotype); altitude, 5.0 millimeters; latitude, 8.5 millimeters.

4. Interior of left valve (cotype); altitude, 5.0 millimeters; latitude, 8.5 millimeters. 

FIGURES 5-6. Corbula (Caryocorbula) wakullensis Gardner, n. sp. (p. 232).

5. Exterior of right valve (cast of external mold); altitude, 4.5 millimeters; latitude, 8.0 millimeters.

6. Internal mold of double valves (type); altitude, 4.8 millimeters; latitude, 9.0 millimeters. 

FIGURE 7. Corbula (Caryocorbula) whitfiddi Dall (p. 232). Exterior of right valve (type); altitude, 5.0 millimeters; latitude, 7.0

millimeters. (After Dall.) 

FIGURES 8-9. Corbula (Caryocorbula) whitfieldi stikta Gardner, n. subsp. (p. 232).

8. Double valves (type) from left side; altitude, 4.5 millimeters; latitude, 7.2 millimeters.

9. Exterior of right valve (type); altitude, 4.5 millimeters; latitude, 7.2 millimeters. 

FIGURES 10-13. Corbula (Caryocorbula) whitfieldi boyntoni Gardner, n. subsp.? (p. 233).

10. Exterior of left valve (cotype); altitude, 3.5 millimeters; latitude, 5.3 millimeters.

11. Interior of left valve (cotype); altitude, 3.5 millimeters; latitude, 5.3 millimeters.

12. Exterior of right valve (cotyp"e); altitude, 4.0 millimeters; latitude, 5.6 millimeters.

13. Interior of right valve (cotype); altitude, 4.0 millimeters; latitude, 5.6 millimeters. 

FIGURES 14-17. Corbula (Caryocorbula) parawhitfieldi Gardner, n. sp. (p. 233).

14. Exterior of right valve (cotype); altitude, 4.8 millimeters; latitude, 6.8 millimeters.

15. Interior of right valve (cotype); altitude, 4.8 millimeters; latitude, 6.8 millimeters. 

*16. Interior of left valve (cotype); altitude, 4.7 millimeters; latitude, 6.3 millimeters.

17. Exterior of left valve (cotype); altitude, 4.7 millimeters; latitude, 6.3 millimeters. 

FIGURES 18-21. Corbula (Caryocorbula) semenoides Gardner, n. sp. (p. 234).

18. Exterior of right valve (cotype); altitude, 3.5 millimeters; latitude, 4.0 millimeters.

19. Interior of right valve (cotype); altitude, 3.5 milimeters; latitude, 4.0 millimeters.

20. Exterior of left valve (cotype); altitude, 3.0 millimeters; latitude, 4.5 millimeters.

21. Interior of left valve (cotype); altitude, 3.0 millimeters; latitude, 4.5 millimeters. 

FIGURES 22-25. Corbula (Caryocorbula) funiakensis Gardner, n. sp. (p. 234).

22. Exterior of right valve (type); altitude, 3.0 millimeters; latitude, 4.3 millimeters.

23. Interior of right .valve (type); altitude, 3.0 millimeters; latitude, 4.3 millimeters.

24. Exterior of left valve (type); altitude, 3.0 millimeters; latitude, 4.3 millimeters.

25. Interior of left valve (type); altitude, 3.0 millimeters; latitude, 4.3 millimeters. 

FIGURES 26-28. Corbula (Bicorbula) idonea Conrad (p. 235).

26. Exterior of right valve; altitude, 2.8 millimeters; latitude, 3.3 millimeters. (After Glenii.)

27. Interior of right valve; altitude, 2.8 millimeters; latitude, 3.3 millimeters. (After Glenii.)

28. Interior of left valve; altitude, 2.5 millimeters; latitude, 3.3 millimeters. (After Glean.) 

248
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXXV

27 16

MYACKA OF THE ALUM BLUFF GROUP

17
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 142 PLATE XXXVI

A1YACEA AND DISCINACEA OF THE ALUM BLUFF GROUP
PLATE XXXVI

FIGURES 1-2. Corbula (Bothrocorbula) synarmostes Dall (p. 235).

1. Exterior of left valve (type); altitude, 9.0 millimeters; latitude, 13.5 millimeters. (After Dall.)

2. Interior of right valve (type); altitude, 9.0 millimeters; latitude, 13.5 millimeters. (After Dall). 

FIGURES 3-7. Corbula (Bothrocorbula) radiatula Dall (p. 236).

3. Interior of right valve (type); altitude, 8.6 millimeters; latitude, 13.0 millimeters. (After Dall.)

4. Interior of left valve (type); altitude, 8.6 millimeters; latitude, 13.0 millimeters. (After Dall.)

5. Exterior of left valve (type); altitude, 8.0 millimeters; latitude, 13.0 millimeters. (After Dall.)

6. Interior of right valve (juvenile); altitude, 5.5 millimeters; latitude, 8.5 millimeters.

7. Exterior of right valve (juvenile); altitude, 5.5 millimeters; latitude, 8.5 millimeters. 

FIGURE 8. Corbula (Caryocorbula) barrattiana C. B. Adams (p. 232). Exterior of left valve (not the type); altitude, 5.0 millimeters;

latitude, 8.0 millimeters. Neill's Eddy Landing, N. C. (lower Pliocene, Waccamaw). 

FIGURES 9-10. Spheniopsis americana Dall (p. 237).

9. Exterior of left valve (type); altitude, 2.0 millimeters; latitude, 3.0 millimeters. (After Dall.)

10. Interior of right valve (type); altitude, 2.0 millimeters; latitude, 3.0 millimeters. (After Dall.) 

FIGURES 11-12. Panope para whitfieldi Gardner, n. sp. (p. 237).

11. Exterior of left valve (type); altitude, 48.0± millimeters; latitude, 90.0± millimeters. (After Dall.) 

12. Apical view of double valves (type); latitude, 90.0± millimeters; diameter, 33.0 millimeters. (After Dall.) 

FIGURE 13. Gastrochaena rotunda Dall (p. 238). Exterior of left valve (type); altitude, 7.0 millimeters; latitude, 3.5 millimeters.

(After Dall.) 

FIGURE 14. Gastrochaena dodona Gardner, n. sp. (p. 239). Exterior of right valve (type); altitude, 6.2 millimeters; latitude, 2.7

millimeters. 

FIGURES 15-16. Gastrochaena ligula H. C. Lea (p. 239).

15. Exterior of right valve; altitude, 4.5 millimeters; latitude, 2.0 millimeters.

16. Interior of left valve; altitude, 4.5 millimeters; latitude, 2.0 millimeters. 

FIGURES 17-20. Discinisca lugubns Conrad (p. 240).

17. Exterior of dorsal valve; altitude, 17.0 millimeters; latitude, 17.8 millimeters. (After Glenn.)

18. Exterior of dorsal valve; altitude, 25.0 millimeters; latitude, 26.0 millimeters. (After Glenn.)

19. Interior of dorsal valve (not the type); altitude, 17.0 millimeters; latitude, 17.8 millimeters. (After Glenn.)

20. Interior of dorsal valve (not the type); altitude, 25.0 millimeters; latitude, 26.0 millimeters. (After Glenn.) 

FIGURES 21-22. Discinisca aldrichi Gardner, n. sp. (p. 239).

21. Interior of dorsal valve (type); altitude, 9.5 millimeters; latitude, 9.5 millimeters.

22. Exterior of dorsal valve (type); altitude, 9.5 millimeters; latitude, 9.5 millimeters.

249

INDEX

A Page 

Abra (Leach MS.) Lamarck.. .---___-__.---______ -_.. -_._.. £09

cylicion Gardner, n. sp... -___-___ 209-210, PL XXXII 

holmesii Conrad____...______ ________-.___--___________ 206

lapochi Gardner, n. sp................................... 209, £10, PL XXXII

triangulata Dall____.__........................_.._____ 210

Adams, H. and A., cited.._____...............................____ 200

Agina of authors_ __________............................. ____ 229

AginaTurton.__......................................................... 227

Aldrich, Truman H., work of--.-...-.-.-. ---.---.--..-.---.--.____ 216,240

Aloidis Muhlfeldt. See Corbula.

Aloidis of authors.________...___....._........._.__.__ 229

Anatina trapezoides Lamarck..--...-.-.....-.-...-..._.-.-.--.-----.._, 226

Angulus. See Tellina.

Arcopagia. See Tellina.

Astartacea..._._....-..-.__...___.___ .._ _._.__... ... . . . 205

Bicorbula. See Corbula. 

Bothrocorbula. See Corbula.

B

Caestocorbula Vincent.._...---.. .__ .... 227,229

Caryocorbula. See Corbula.

Chipola formation, Florida, distribution of species in......_.--.--.....- 186-187

Conrad, T. A., cited.._-..-. -. -..............-.....---.-.---.-.--..-. 218

Corbula (Bruguiere) Lamarck ............................................ 226-228

Corbula s.l__...............-.-......-...-.-........--.-....... ...- . £28

S. s______________...............................__._.__. 228, £29

acutangula Rissel_______................................._...... 226

alabamiensis Isaac Lea.-..........-.....--....----....-............_ 230,231

aldrichi Meyer__._____.....................___________ 234

barrattiana C.B.Adams.--..............--.....-..-.-.- 228,232, PI. XXXVI

biangulata Deshayes-- -._............._--.---....________. 227

chipolana (Dall MS.) Gardner, n. sp............. . 228,220,230, PI. XXXIV

engonata Conrad________....... ...______________.. 228

var. burnsiiDall.-. -.-.--.-..--... ................ 231,235,236

gallica Lamarck._______.____._...___________ 226,227,228,235 

gibba(Olivi).................................................. 226,227,228,229

guineensis Muhlfeldt_______..._.........._____........._ 226

henckeliusi Nyst.___......___...-......-.--..-......_.--...._ 227

idonea Conrad._____......................._._.............._ 235

laevigata Lamarck..._____._______________.____ 226 

margaritaceaLamarck..________._._.......______... 226,227

nucleataDall_________.___.................._..._______ 234

nucleus Lamarck___.______._...........__________ 226,227

porcina Lamarck_____..._......._........_.....___...... 226

striata Lamarck.____...._..._...._....._..........___... 227

subcontracta Whitfleld___._______...._.________.._ 232

sulcata Lamarck._______............._...._______... 226,227

vieta Guppy.. _______.__.__.___.______.___._.. 230 

Viminea Guppy__............................................... 228,235,236

waltonensis Gardner, n. sp________......_._ 228,229-£30, PL XXXIV

(Aloidis) Muhlfeldt-_.. .... ..................................... 227

heterogenea (Guppy MS) Dall._________..._.__. 228,229,230 

Bicorbula Fischer.-._.____ .................................. 227-228,228,235

sp. indet....______.__..._....___...___________ £35

(Bothrocorbula) Qabb................................................ 228,235

radiatulaDall. .......... ....................... 228,£36, PLXXXVI

var. tenella Dall_.._...._._.__.__._____.___ 236

synarmostes Dall . 228, 231, £35-£36, PL XXXVI 

viminea Guppy.___. - -. ....... ..____________ 235

(Caryocorbula) Gardner........ ........._.....___________ 227,250

antoniae Maury.._......_.-.-.--..-............_______ 228,2S£

franci Gardner, n. sp..........._................. 228,£SJ-«£, PI. XXXV

funiakensis Gardner, n. sp._____..__.__._._ 228,£34-£35, PL XXXV

parawhitfleldi Gardner, n. sp................. 228,232,23S-£34, PL XXXV

sardaDall..- . _ 228, 8S1, 232, PL XXXIV 

seminellaDall. ... ...... . 228,234,235, PL XXXIV

semenoides Gardner, n. sp......_..._....._.___ 228,£34, PL XXXV

sphenia DalL.--..-.---....-.-....----.....--.... 228,230-23/, PL XXXIV

wakullensis Gardner, n. sp____. __________ 228, 838, PL XXXV

Corbula (Caryocorbula) whitfieldi Dall.._...... . 228,£S£, 233,234, PL XXXV

boyntoni Gardner, n.subsp.. . 228, 232, £SS, PL XXXV

stikta Gardner, n.subsp ._._ 228,23£-£3S, PL XXXV

(Cuneocorbula) Dall and authors....... ... . ... 227,230,232,234,235

dominicensis Gabb__ _-_______________._________ 231

D 

Dall, W. H., cited..._.... 189,190,191,192,193,194,

195,196,197,198, 200,201,203-204, 204, 205, 208, 209, 211,214, 216, 217,218-

219, 219, 220, 221, 222, 223, 224, 226, 230, 231, 232, 234,235,236,237,238, 239

Discina lamellosa Broderip..--------------------------- .--. - -. 239

DisciniscaDall.-..-_. .............___.... _.__.________ £59

aldrichi Gardner, n. sp................................... £39-240, PL XXXVI

lugubrisConrad ... 239, 240, PL XXXVI

Distribution of the fauna-- --- -. - ------ m-rv

Donax (Linnaeus) Lamarck,.._.__.......-......-.-.--..__.... ._.. £//

Donaxs. s..-_..._____ ----. ..____......._...._____.. ill

chipolanusDall .. ... ill, PL XXXII

subsp.?eurtulus DalL.._.._....-.--....----.--.-.-... 811-ilg, PL XXXII

denticulata Linnaeus.----------............---.....--..-_..._------ 212

emmonsi DalL. ... ......-... .. .. ... ......._ 211,213

fossor Say .. . . . . 211,213 

rugosa Linnaeus....__.._........_..-.-..--....--.__.----..---.-- 211

sp ................ . .... . . - £/£

striata Linnaeus__.__..._................_.__..._._..- 212

transversa Deshayes -........___._____.__..._...___... 212,213

trueloides Gardner, n. sp.................................. 211,318, PL XXXII

variabilis Say-----...________...._________.______._ 211

(Paradonax) Cossmann............_...__.._-------------- - £/£

aldrichi (Dall MS.) Gardner.... .... . 211,2?£-2/3, PL XXXII

valhosierr Gardner n. sp.............................. 211, US, PL XXXII

E

Easis Schumacher.......---..------.--------..-...-.-.._.__. ... H7-818

ensiformis Conrad__._.............._---------___....... ..--. 218

magnus Schumacher.--.-.__---....- -..----__-._______-----._ 217

sp. cf. E. directus (Conrad)...... . -.- . il8, PL XXXIII

ErviliaTurton ___..... .. .. .. .... ................ ££S-££4

chipolanaDall . _- . .. *t4, 225,226, PL XXXIV 

subsp. triangularis Dall. . ££4~££5, PI. XXXIV

concentrica Gould______...._.__....___.___._ .__ 224

condra Gardner, n. sp. .. 224, ££5, PI. XXXIII

lataDalL--. 225

planataDall.... .... 224, £26, PI. XXXIV

valhosierr Gardner n. sp.,.......... .. 224, M5-W6, PI. XXXIV

Ervilinae_______._... ._. .. ._-.- .................. ££S

Eurytellina. See Tellina [Arcopagia].

G

Gastrochaena Spengler......-.-_-----------_....... .--... £88

cuneiformis Spengler._. _....... ......________-_____ 238,239

dodona Gardner, n.sp.--...---... .. 238, £39, PI. XXXVI

ligula H. C. Lea, 1898. . 239, PI. XXXVI

ovata var. rotunda Dall...------.----------------------- ... 238

rotunda Dall.-. . - - - £38-239, PI. XXXVI

Gray, J. E., cited.-----. - 222

Hemimactra. See Spisula.

H

M

Macaliopsis _______......--.-- ... ................ 192

Macoma Leach..... ______._ £00-£0.

calhounensis DalL__.._ ..-.. - ..... . ... £0.

constricta Bruguiere--..------------- ._- ,__- --- .. 201

lenis Conrad-------..----------------------------------- --- 201

paralenis Gardner, n.sp- ....-- ----------- - SOI, PL XXX

tenera (Leach)-._ _......--.---------------.------.----------- 201

(Psammacoma) Dall-..--_---------------------,-. .-_.. 20.

marmoreaGardner.n.sp.----------------------- 201, £0£-20S, PL XXXI

torynoides Gardner, n. sp . 201, £0£, PL XXXI

tractaDall - 20£, 203, PI. XXXI
II INDEX

Macoma? calhounensis Dall..__...._.......................__.-.-... 195

Mactra Linnaeus________.___._..........___._...__... 2/9,220

Mactras.s................................................................ 2/9,223

californica Conrad......__...._.................__.....___.__ 220

chipolana Dall.............................................. 2/9, PL XXXIII

edulis King..__.___ __.__.... 222

fragilis Gmelin..__.....__......................._.............. 220

solida Linnaeus...._----..--.-----.-.--.---........................... 220

spengleri Linnaeus..-.-..-.----.---..----.....------......-............. 219

stultorum Linnaeus.---........-.---------..--........_............... 219

tenuis Montagu___.__................_.............__._... 209

undulaDall. .-- 220

(Mactrotoma) Dall -..---..--.----.--.-..---.-.- .-..._..... 2/9-220 

cymata Dall. . .- ---- ........ 219, MO, PI. XXXIII

Mactracea Gray.. ..... .....-...-..... .......,. .... ........ 2/8-2/9

local distribution of species of_--.-.----.---..-...-__............. 186-188

Mactromeris Conrad___________.__...______.______... 222

Mactrotoma. See Mactra.

Maury, C. J., cited..._...-... ... ..----............. ...... ..... 232

Merisca. See Tellina.

Mesodesmatidae Deshayes..__.___...___.._______.._.___ 223

Mesopleura. See Tagelus.

(Solen) bidentata Spengler..__.__. _..._________..____ 214

Metis H. and A. Adams..--.... . -. .-.- .-- .................. 200

chipolana Dall..___. .. .. ..... .. 200, PI. XXX

dombeyi...__..__._.... ---. ... . . .-..... -. 200

Micromactra Dall_____.-.------.---.--.-.-..-.......................- 220

Moerella. See Tellina.

Molluscoidea, local distribution of species of......__--. _........_ -... 186-188

Mulinia Gray__..... . ..... .. ...-.. . 221,222-223

congesta Conrad..___________-. ---.. ..... ._..___ 221

lateralis subsp. corbuloides Deshayes...._. _ _.-.--.---_ 223

orthria Gardner, n. sp......... . .. .. .._._ ... 22S, PI. XXXIV

typicus Gray._____.. ........-. .... ... ....... ._......._ 222

Myainaequivalvis Montagu...._.. . ___ . _........... 227

nitens Montagu.___._.-------.--------.-.-----..----..--....-..-.- 223

purpurea Montagu____.__-------__._______________._ 227

Myacea, local distribution of species of._______...__...__.... 186-188

O

Oak Grove sand, Florida, distribution of species in______________ 186-187 

Georgia, distribution of species in.-..--.._...._____..___ 186-187

Panope Menard de la Groye.. _____._...._.-..____..___... 237 

aldrovandi Menard dela Groye--___....___._.________ 237 

parawhitfieldi Gardner, n. sp... .. -.... .. 237-238, PI. XXXVI 

sp.indet.----. --_. . .---- ---. ... . . .. 238 

whitfleldiDall-.-.. . ..- . _ . 237,238

Paradonax. See Donas.

Phyllodina. See Tellina.

Psammacoma. See Macoma.

Psammobia Lamarck.._________.____._.._________ 2/3-2/4 

bowdichi Gardner, n. sp..______._.___ - .... 2/4, PI. XXXII 

papyria Conrad.._________.____.__.___._______ 214

Psammobia Risso.____.__________ -- . _ _. _._... 215

Psammosolen vicksburgensis Aldrich______..-.__... ..____... 216

Psamosolen Risso.____________.-..-.-__.__._.______ £15-816 

aldrichi Gardner, n. sp._ .. . .. 2/6, PI. XXXIII

sanctae-marthae (D'Orbigny)_________. ...._______ 216

sp . ______________......______.___..._______ 2/6

Pseudarcopagia..________________...___.....______ 192

Saxicava arctica (Linnaeus)...-_..--.-.--.-..-----...--._...-.-.---.-.-- 227 

Say, Thomas, cited -- - - - - . 192

Scissula. See Tellina.

Scope of the paper_____.___......____.._....__._____ 185

Semele Schumacher.________..._.___.__..___________ 20S 

Semele s. s...._________.....-----...--...----. .........___. 203-204

bella Conrad._............. 203,204,205,207

cancellata Orbigny....__.__.__ ... _.. _............__ 204,205

carinata Conrad____.....-...-.---------.-.---.....-._____..... 203,206

chipolanaDall.. _ 203,204, PI. XXXI

compactaDaU.... . .. ...... 203,205-206,207, PI. XXXI

leanaDall_________... .... ... _______________ 203,204

muticaDall ... ..... .... 203,204,205,206,207, PI. XXXI

nuculoidea Conrad____._...____.____________.. 203,208 

var.striulata Dall----.---..---..--.-.__....__...__... 208

paramutica Gardner, n.sp .... .-. 203,206,207, Pis. XXXI, XXXII

perlamelloides Maury......._......._......____..___..__ 204

perlamellosa Heilprin___................____...._._......... 203

scintillataDall.. .. .. 203, 204, 205, PI. XXXI

Semele sellardsi Gardner, n. sp............ ...... - 203, 207-208, PI. XXXI

smithiiDall.. ......... -..-..... -.. 203,204, PI. XXXI

stearnsii Dall 203,204,205,207, PL XXXI

subovataSay_____.......__ . . .________ 203,207,208

taracodes Gardner, n.sp 203,£06-207, PL XXXI

(Semelina)Dall..... . ... . 203,208

cythereoideaDall . 203,208-209, PL XXXII

striulata Dall. ................................._... 203,209, PL XXXII

SemelidaeDall . . - - 203

Semelina. See Semele.

Semelinanuculoides Conrad____...__-__......................... 208

Shoal River formation, Florida, distribution of species in ------------- ... 188

Siliquasubaequalis Gabb__- - ------------------------_--------- --- 215

Siliquaria Schumacher.._....-.-...-...-.-.-.-.-.....-----.---------- .. 214

Solen (Linnaeus) Lamarck........-....... -.- ... .. .. .. . .2/7,218

amphistemma Dall ------___-_-_-___-_-_-_-_-_.--_.--- 2/7, PL XXXIII

directus Conrad-------.----------------------.------------.--.- 218

divisus Spengler----.---.-----.---.------------.----.----------_-_ 214,215

ensis Lamarck--------.--------_-_---_-----_-----_----------.--.---- 218

gibbus Spengler.-- - - - - - - 214

marginatus Pulteney __ - 217

strigilatus Linnaeus...__ . . -- _.... -- -. 215

vagina Lamarck........... ......-.-.-.-.-.-..... ........-.. .. 217

Solenacea Lamarck .___... _ _ . . 2/6

local distribution of species of . .-..--.. - 186-188

Solenidae Leach......_ ........ ... ......-.. . 2/7

Spheniopsis Sandberger.____ .. ...__......___ 236-237

americanaDall. . 237, PL XXXVI

scalaris Brown_..._.--.- .----.- ------. ..-----.--.----.- .-.. 236

Spisula Gray . . --.---------- - - 220

delumbis Conrad__ 222

ovalis Gould .--- ------ -- - - 222

polynyma Stimson.--...--....-.. .-...-.--.----... ...-._---------- 222

subponderosa D'Orbigny...------------------------------------------ 222

(Hemimactra) Swainson.-...-. -.... .-. . _. ... ._..._ 220-22/

craspedota Gardner, n. sp.......--.-. --...-. 220, 2S1, PL XXXIII

densaDall 220, 281, PL XXXIII

dodonaDall-.-. -------------------------- 220,222, PL XXXIII

marylandiea DalL- -----_-------_ .... -. . 222

valhosierr Gardner, n.sp 220,222, PL XXXIII

StrigillaTurton..- . 198

carnaria Linnaeus..._ __-.__... 198

eutyka Gardner and Aldrich._...__.............. ...__ . 198

flexuosaSay... . . 198,199

georgiana Gardner, n.sp. 198, 199, PI. XXX

paraflexuosa Gardner, n.sp . - 198, 199, PL XXX

pisiformis Lamarck___.................................. 199

rombergi Morch____.--__....................... .... .-. 198

senegalensis Hanley.____.... ._.--...--- -.--..-.-.---..--.-.-.-. 198

sphaerion Gardner, n.sp- ------------------------- 198,199,200, PL XXX

Syndesmya Recluz 1843..___-_..-.-...-.- ...... 209

Tagelus Gray 2/4,216

divisus (Spengler)....-_------- -- _............._._-.... 215

gibbus (Spengler)-- --------------------------------------- .-.--... 215

Mesopleura Conrad. - - . . .- - - - 2/4-2/5

sp.--- .__.. - -.- . .... -. 2/5

sp. cf. T. divisus Spengler. . . 215, PL XXXII

Tellina (Linnaeus) Lamarck -. -_ 189-190

representation of, in the Alum Bluff group. . _... .- 185 

acalypta Dall ___-..... . .. .... -...- 194,198

alternataSay - - 194,196

angulosa Gmelin......-........-...-... --------------..-....._..-.. 194

calcarea Gmelin.___..-.-_...............-... ............... 201

Candida Lamarck___......-... -..----------.- -.- ...-. -- -..- 201

carnaria Linnaeus.__. ..-.-..---...-..-.----..---.-..-..-... --_... 198

crassa Pennant_____ ____-. . . _------ 191

crystallina (Chemnitz) Wood 191

cumingii Hanley -___ --------- .. . . ..... ..... . 191

decora Say..._____.. .._ ... ._- ... ._ ----- 194

donacina Linnaeus___.__-----.---------------------.----------. 195

feroensis Gmelin-.._ ....- ... . -.... ..-.--.-.- 213

galathea Hanley __.-- --.- --.- .--- -----.---._--.-....--.-- . 201

interrupta Wood..__.--.-.-------.-----_. .........-........ .... 190

lanceolata Linnaeus....------------.------..-----..--.- .-.-.-.-------. 194

merulaDall.____ ... . .... .. ......... 195

meyeri Dunker____.. -. .. ...____._____. .. 200

ostracea Lamarck.. -------- ------------------. ...... ----- 192

polita Say______-------- -------. - _ 197

proficua Pultney.___ - -- - -- - __._ _.. 203 

punicea Born______-___-.-.-..__.._.._------......_--.-. 193

radiata Linnaeus._____-_--------------__-._ _--------- 189
INDEX III

Page 

Tellina reticulata Spengler-__-_..........__...._.... .......__._ 203

rubescens Hanley__..._...................__.............____ 194

simpsoni DalL..._....__......... ..-....................._... 196

squamifera Deshayes______..........................*............_ 192

sybaritica Ball._______......_............._....___.....__ 196

virgata Linnaeus_________._.__........._..___-_._ 189,190

(Angulus)............................................................... 195

acalyptaDall..--.___.__.................._...._._..._ 197

acosmita Dall..._______...................................... 196

agria Dall._______.________................_........ 196

[Arcopagia] (Leach MS.) Thomas Brown.._....._..................-. 191,200

(Eurytellina) Fischer............__......................_._.. 193

pressa Dall............_............................... 194, PL XXIX

roburina Dall................................ 189,194, 197, PI. XXIX

spiekeri Woodring_--..-.-.-.-.---.........---.....-...--.-.... 194

(Merisca) Dall..__..__.. ..-.--..-.-...-...--..-...-.__.__ 191 

aeriuistriataSay. ........ ... 189,192, PI. XXIX

hypolispa Dall................................................ 195,210

(Phyllodina) Dall................................................. 189,192

dodona Dall..... ............................... 192-193, PI. XXIX

leptalea Gardner, n. sp.__._...__._...____.. 193, PI. XXIX

Tellina [Arcopagia (Scissula)] Dall.. ..-............. . 189,194

[Arcopagia (Scissula)] lampra Dall....... . ...".. 194-195, PI. XXX

(Scissula) sp . . . - _.. 195 

(Macaliopsis) cloneta Dall-------------------------------- 195

Moerella Fischer........... .__.... -------.-. .. -_ 192, IBS

acalyptaDall--- .-- - --- - 196,197, PI. XXX

acosmita Dall.-. . . 196, PI. XXIX

acloneta Dall 196 PI. XXX

agria Dall.. 196-197, PI. XXX

cloneta Dall 195, 196,201, PI. XXX

ctenota Gardner, n. sp.-.-. 197,198, PI. XXX

hypolispa Ball.. 195-196, PI. XXX

piesa Gardner, n.sp . 189, 197-198, PL XXX

Tellinella Morch......' ..... . ... ......... 190

chipolanaDall--.- - 190,191, PI. XXIX

strophiaDall . 191, PI. XXlX

waltonensis Gardner, n. sp_ . . 191, PI. XXIX

TellinaceaBlainvUle .- . 189

local distribution of species of... .____ ... 186-188 

Tellinella. See Tellina.

o