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

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UNITED STATES DEPARTMENT OF THE INTERIOR 

Ray Lyman Wilbur, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 170—D

PLIOCENE FOSSILS 

FROM LIMESTONE IN SOUTHERN FLORIDA

BY

WENDELL C. MANSFIELD

Shorter contributions to general geology, 1931

(Pages 43-56)

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON: 1932

For sale by the Superintendent of Documents, Washington, D. C. ------------------ Price 15 cents
CONTENTS

Page

Abstract_________________________________________ ____________________________________________________________ 43

Introduction _________________________________________________________________________________________________ 43

Former work in the area______________________________________________________________________________________ 43

Geographic occurrence, matrix, and faunal composition_________________________-___-______--_---______-_--_-_-____ 43

Geologic occurrence._._--_---_--__-_________________________ ________________________________________________ 44

Nature of the faunas __________________________________________________________________________ _____________'__ 45

Age of the faunas_____________________________________________________________________________________________ 45

Relationship to other faunas.__________________________________________________________________________________ 45

Descriptions of new species____-________________-________________________-_____________------__-_---_-----__-__ 46

ILLUSTRATIONS

Page 

PLATES 14-18. Pliocene fossils from limestone in southern Florida._________________________________________________ 51

n
PLIOCENE FOSSILS FROM LIMESTONE IN SOUTHERN FLORIDA

By WENDELL, C. MANSFIELD

ABSTRACT

This paper describes the mollusks and echinoids found 

in limestone dredged from ditches along the Tamiami Trail 

in southern Florida, in the area mapped as "Lostmans River 

limestone (Quaternary)" by Sanford but included in the 

Pliocene Caloosahatchee formation by Cooke and Mossom on 

the evidence of these fossils as identified by Mansfield. The 

matrix of the fossils is unlike the typical Caloosahatchee 

formation, which is sandy, but the fauna is closely related 

to that of the upper part of the Caloosahatchee formation 

and is regarded as a facies of the Caloosahatchee. The fauna 

shows considerable resemblance to that of the Imperial formation of California but may not be contemporaneous with it.

INTRODUCTION

The fossils upon which this paper is based were 

collected in February, 1927, by C. Wythe Cooke, geologist, of the United States Geological Survey, Stuart 

Mossom, then assistant on the Florida Geological Survey, and W. C. Mansfield. The five collections here 

reported upon were obtained along the Tamiami Trail 

within a northwest-southeast distance of about 34 

miles, in Collier and Monroe Counties, Fla. The 

fossils were embedded in white or gray limestone, here 

referred to the Caloosahatchee marl, which had been 

dredged from shallow ditches to form the roadbed of 

the Tamiami Trail and which was not observed in 

place. Cooke and Mossom1 give a brief account of 

these collections, referring them to the Pliocene. 

These collections are of considerable interest because 

they extend the range of Pliocene faunas much farther 

south than they had been known before.

I wish to express my sincere thanks to L. W. Stephenson and C. Wythe Cooke, of the United States Geological Survey, and to Austin H. Clark, of the United 

States National Museum, for helpful assistance.

The photographs for the illustrations of this paper 

were made in the laboratory of the United States Geological Survey by W. O. Hazard, and the prints were 

retouched by Miss Frances Wieser.

FORMER WORK IN THE AREA

The fossils described in this report were collected 

in the area formerly mapped under the name " Lostmans River limestone," proposed by Sanford 2 for a 

dark to light crystalline to brittle limestone that is

1 Cooke, C. W., and Mossom, Stuart, Geology of Florida: Florida 

Geol. Survey Twentieth Ann. Rept, p. 156, 1929.

3 Sanford, Samuel, The topography and geology of southern Florida: 

Florida Geol. Survey Second Ann. Rept., p. 222, 1909. 

72013°—32

sandy in places. The type locality of the " Lostmans 

River limestone " is on the Lostmans River, Collier 

County, about 15 miles south of station 1/1179, one 

of the localities at which the fossils described in the 

present paper were collected. Sanford referred the 

<k Lostmans River limestone" to the Pleistocene. 

Cooke and Mossom,3 however, did not adopt this name 

but mapped the area formerly outlined by Sanford 

for this limestone in part as Miami oolite (Pleistocene) and in part as Caloosahatchee marl (Pliocene). 

The area in which the fossils here described were 

collected is mapped by Cooke and Mossom as the 

Caloosahatchee marl, and the area at the type locality 

of the "Lostmans River limestone" as the Miami 

oolite. Cooke and Mossom evidently considered the 

" Lostmans River limestone " equivalent in age to the 

Miami oolite.

Dall and Harris 4 described the rock at the Lostmans River as being very hard and compact and consisting of large masses of Polyzoa more or less completely changed into crystalline limestone, the cavities 

filled with crystals of calc spar. The only mollusk 

reported from this limestone was a single valve of 

Ghione cancellata. (Linnaeus), a species ranging in age 

from the Pliocene to the Recent. This species was 

found only at one locality (station 1/1177) among 

the collections described in the present paper.

As I have not seen samples of limestone or organic 

remains from the type locality of the " Lostmans 

River limestone," I do not know whether the rock in 

which the fossils here described were found is the 

same as the " Lostmans River limestone " or a different limestone, but I am of the opinion that it is different.

GEOGRAPHIC OCCURRENCE, MATRIX, AND FAUNAL 

COMPOSITION

The following is a brief description of the material in which the fossils were embedded, based on 

the matrix attached to the fossils, and a brief account of the kinds of organisms found at each locality.

Station 1/1176. Tamiami Trail, about 11 miles east by 

north of Marco, Collier County. Dirty-white to gray, rather 

hard, porous, nonoolitic limestone with inclusions of clear 

angular quartz grains. The cavities were originally occupied 

by the tests of organisms, mainly mollusks. Some of these 

cavities are now partly filled with small, rounded, attached

3 Cooke, C. W., and Mossom, Stuart, Geology of Florida: Florida 

Geol. Survey Twentieth Ann. Rept., p. 207, 1929.

4 Dall, W. H., and Harris, G. D., The Neocene of North America: 

U. S. Geol. Survey Bull. 84, p. 100, 1892.

43
44 SHORTER CONTRIBUTION'S TO GENERAL GEOLOGY, 1931

limy bodies. The fauna consists of small and large mollusks, bryozoans, and barnacles. To judge from the nature 

of the matrix, all the organisms came from the same bed.

Station 1/1178. Tamiami Trail, about 6 miles west of the 

crossroads leading to Everglades, Collier County. The matrix 

is similar to that at station 1/1176. The fauna consists of 

large mollusks, bryozoans, foraminifers, and echinoids. The 

nature of the matrix indicates that all the fossils came from 

the same bed.

Station 1/1180. Tamiami Trail at Carnestown, 4 miles 

north of Everglades, Collier County. The matrix is similar 

to that at stations 1/1176 and 1/1178. The fauna consists 

of large mollusks, echinoids, bryozoans, and many small 

foraminifers. The nature of the matrix indicates that all 

the fossils came from the same bed.

Station 1/1177. Tamiami Trail, 5 miles east of Carnestown and about 7 miles northeast of Everglades, Collier 

County. The matrix is similar to that at the localities above 

described. The fauna consists of large mollusks, bryozoans, 

foraminifers, and echinodermg. The presence of the species 

Chione cancellata (Linnaeus) in this collection may indicate 

that it came from a stratigraphically higher limestone, as 

this species was not recognized with certainty in the other 

collections.

Station 1/1179. Tamiami Trail, 9 miles west of Pinecrest, 

in sec. 13, T. 54 S., R. 32 E., Monroe County. The matrix is 

mainly similar to that at station 1/1177 but slightly more 

compact and harder. The fauna consists of large mollusks, 

one species of echinoid, bryozoans, and barnacles. To judge 

from the nature of the matrix, probably most if not all the 

fossils came from the same bed.

GEOLOGIC OCCURRENCE

Although the conditions at the localities at which 

the fossils were collected did not afford data for determining the thickness of the limestone, Sanford 5 

reports that a well drilled at Everglades, 4 miles south 

of station 1/1180 of this paper, passed through 30 feet 

of limestone (presumably the same as the fossil-bearing limestone farther north) and 40 feet or more of 

fine gray sand beneath it:

Fossils, either of upper Miocene or Pliocene age, 

have been collected by members of the Florida Geological Survey along the Tamiami Trail 42 miles west 

of Miami (about 13 miles east of station 1/1179) in a 

beachlike sand, which is overlain by a 3-foot bed of 

hard yellow limestone containing Chione cancellata. 

The limestone may be a little younger than the fossilbearing limestone treated in this paper, and the sandy 

bed may represent the sandy bed beneath 30 feet of 

limestone at Everglades. If these sands are contemporaneous, the overlying limestone bed or beds thicken 

westward. Sufficient information has not been obtained to determine definitely whether there is one 

limestone or more in this area.

B Sanford, Samuel, The topography and geology of southern Florida: 

Florida Geol. Survey Second Ann. Kept., pp. 208, 223, 1909.

Species and geologic range

GASTKOPODS

Terebra dislocata Say__ ______ _ _ _____

Fasciolaria sp___ _ - ___ _________ ___

Strombus sp_______ ^ _ _ _ __

TurriteUa, n. sp.? aff. T. perattenuata Heilprin_ _ _ _ ___ _

Calyptraea sp___ _ _ _ - ____

Crucibulum sp______--_-_ ______ _ _____ _ ___ __ __

PELECYPODS

Glycymeris pectinata (Gmelin)?-- _____ _____ _ __

Pinna sp_.__ __ __ _ _ _____ ______ _____ _ ______

Ostrea sculpturata Conrad... ______________ _ _ _

Cardium sp

ECHINOIDS

1/1176

?

X .

X 

X

X 

X

X

X

X

1/1178

X 

X 

X

X

X

X

X 

X 

X

X 

X

X

X

X 

X

X

1/1180

X

X

X 

X

?

X

X 

X

X

X 

X

X

X

X

1/1177

X

X

X

X

X 

X

? 

X

X

X 

X

1/1179

X

X 

X 

X

X

X

X

?

X

X

Miocene

X

X

X

X

X

Pliocene

X

X

X

X

X 

X

X

Recent

X

X

X

X

• Same form as in the Pliocene at Alligator Creek, Fla.
PLIOCENE FOSSILS FROM LIMESTONE IN SOUTHERN FLORIDA 45

NATURE OF THE FAUNAS

The faunas include 6 genera of gastropods, 15 genera 

of pelecypods, and 2 genera of echinoids. Aside from 

these, Foraminifera, barnacles, and Bryozoa were observed at a few localities. Among the pelecypods the 

scallops and oysters are the most conspicuous forms, 

both in the number of species and individuals and in 

the rather large size which some of them attained. 

The echinoid, Encope maarophora tamumiiensis Mansfield, n. subsp., was found at three localities, and the 

new species CassidwlMS evergladensis at two localities.

The character of the faunas indicates that they lived 

near the shore in comparatively shallow water.

AGE OF THE FAUNAS

Although fossils collected from spoil banks may 

come from more than one bed, nevertheless most of 

the fossils obtained at these five localities appear to 

have come from the same bed. However, the occurrence of Chione candellata at station 1/1177 may indicate that it came from a higher bed at that place; 

and the occurrence of the new subspecies Ostrea tamviamiensis monroensis at station 1/1179 may indicate 

that it came from the higher of two beds at that place. 

The ditches were partly filled with water at the time 

the fossils were collected, and a full section of the 

cut was not revealed.

The age of the faunas is believed to be Pliocene. 

Although the collections include some forms that were 

not found elsewhere and consequently are of little aid 

in correlation, a few are like or closely allied to Pliocene forms, such as Ostrea, group of O. triffonaMs, 

Pecten evergladensis, and Encope mdcrophora tamiamiensis. On the other hand, one form, Cassidlulus 

everglacfiensis, apparently shows some relationship to a 

species occurring in the Oligocene. Nevertheless, one 

specimen, borrowed for comparison from the Florida 

Geological Survey, collected at Moore Haven, Glades 

County, Fla., and probably dredged from the canal, 

agrees in detail with C. evergladensis. No fossils older 

than Pliocene have been dredged from the canal in the 

vicinity of Moore Haven. However, the faunal f acies 

and the apparent stratigraphic relation of the fossiliferous bed to other formations in southern Florida 

suggest strongly a Pliocene rather than an earlier age.

Some poorly preserved specimens of Foraminifera 

from stations 1/1177 and 1/1180 were submitted to 

Dr. Joseph A. Oushman for identification. Those 

from station 1/1177 were unidentifiable, but in the 

lot from station 1/1180 were found Amphistegina 

lessonii D'Orbigny, Eponoides sp. ? (probably the 

same as one of our living species off the coast), and 

some internal casts of Qmnqueloculina, and TrUoculina. Doctor Cushman states that "these are not 

sufficient to place the material with any degree of 

accuracy, but it is apparently Pliocene or Pleistocene."

RELATIONSHIP TO OTHER FAUNAS

The faunas from the Tamiami Trail compare most 

closely with those at Alligator Creek, Charlotte County, 

Fla., which Dall 6 regarded as younger than the fauna 

occurring at Shell Creek, a tributary of Prairie Creek, 

Charlotte County, Fla., and assigned to the Pliocene 

Caloosahatchee marl.

The faunas of southern Florida appear to be related to those occurring in the Imperial formation— 

the marine deposits bordering Carrizo Mountain 

(sometimes called Coyote Mountain), Imperial 

County, Calif.; in fact, they appear more closely 

related to the Imperial faunas than to any other 

remote fossil faunas I have seen.

The Imperial formation, proposed by Hanna in 

1926, was redefined by Woodring 7 and made to embrace the entire series of marine deposits bordering 

Carrizo Mountain, and to exclude the overlying nonmarine beds. In referring to this formation I have 

followed Woodring's definition of it.

The marine beds of the Imperial formation have 

been called "doubtfully Cretaceous," Miocene, and 

Pliocene.

Vaughan,8 relying upon two species of coral, originally referred them doubtfully to the Cretaceous.

Arnold 9 first called them lower Miocene, or simply 

Miocene, but later 10 referred them to the upper Miocene and correlated them with the Etchegoin formation of California. The Etchegoin formation is now 

considered of Pliocene age.

Vaughan, in a later paper,11 concluded that "the 

systematic affinities of the fauna of Carrizo Creek are 

with the Caloosahatchee Pliocene of Florida and the 

Pleistocene and living faunas of the Antilles."

Dickerson 12 states: " Several species appear to be 

identical with forms which are characteristic of the 

Gatun formation, of Miocene age."

Kew,18 in his studies of the echinoids, referred the 

beds to the Pliocene.

• Dall, W. H., Contributions to the Tertiary fauna of Florida: Wagner Free Inst Sci. Trans., vol. 3, pt. 6, p. 1604, 1903.

7 Woodring, W. P., Distribution and age of the marine Tertiary deposits of the Colorado Desert: Carnegie Inst. Washington Pub. 418, 

p. 7, 1931.

8 Vaughan, T. W., The Eocene and lower Oligocene coral faunas of 

the United States: U. S. Geol. Survey Mon. 39, p. 19, 1900.

9Arnold, Ralph, The faunal relations of the Carrizo Creek beds of 

California [abstract] : Science, new ser., vol. 19, p. 503, 1904; The 

Tertiary and Quaternary pectens of California: U. S. Geol. Survey 

Prof. Paper 47, p. 21, 1906.

"Arnold, Ralph, Paleontology of the Coalinga district, Calif.: U. S. 

Geol. Survey Bull. 396, p. 44, 1909. Arnold, Ralph, and Anderson, 

Robert, Geology and oil resources of the Coalinga district, Calif.: 

U. S. Geol. Survey Bull. 398, p. 1394 1910.

11 Vaughan, T. W., The reef-coral fauna of Carrizo Creek, Imperial 

County, Calif., and its significance: U. S. Geol. Survey Prof. Paper 98, 

p. 367, 1917.

33 Dickerson, B. B., Mollusca of the Carrizo Creek beds and their 

Caribbean affinities [abstract] : Geol. Soc. America Bull., vol. 29, p. 

148, 1918.

u Kew, W. S. W., Cretaceous and Cenozoic Echinoiclea of the Padflc 

coast of North America: California Univ. Dept. Geology Bull., vol. 12, 

No. 2, pp. 32, 33, 56, 60, 61, 137, 1920
46 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1931

Hanna 14 has more recently published a paper in 

which he gives formational names to the series of deposits about Coyote Mountain, records the faunas, 

and describes eight new species of mollusks. He concludes that the age is not greater than lower Pliocene 

and is inclined to believe that the greater portion of 

the series is middle and upper Pliocene. The illustrations in Hanna's paper were found very helpful for 

comparison with the faunas of southern Florida.

The latest contribution to the paleontology of the 

Imperial formation has been made by Woodring,15 

who says:

The paleontological evidence points to the conclusion that 

the marine beds of the Colorado Desert are of Miocene age, 

and the other two lines of evidence passively support this 

conclusion. There is little on which to base a conclusion 

as to what part of the coastal Miocene section is represented, but the evidence that is now apparent indicates late 

Vaqueros age—that is, late lower Miocene.

I have not studied the faunas of the Imperial formation sufficiently to express a definite opinion as 

to their age or the relative stratigraphic position of 

these beds with respect to those lying along the 

Tamiami Trail in Florida. However, I have observed certain species in the Florida faunas that appear to be related to species occurring in the Imperial 

formation and also to species now living in the Gulf 

of California. This apparent relationship may be a 

facies similarity rather than a genetic similarity.

Species collected from the Pliocene along the 

Tamiami Trail that are apparently related to those in 

the Imperial formation and to those now living in 

the Gulf of California are listed below. The species 

named in the middle column were either originally 

described as from the Imperial formation or have 

been reported to occur there.

Pliocene, southern Florida Imperial formation, California Recent, Gulf of California

Ostrea tamiamiensis Mansfield, n. sp__________

Pecten tamiamiensis Mansfield, n. sp____^____.

Pecten pittieri collierensis Mansfield, n. subsp_. 

Pecten evergladensis Mansfield, n. sp__________

Thracia (Cyathodonta) tristana Olsson?_______

Encope macrophora tamiamiensis Mansfield, 

subsp.

Ostrea heermanni Conrad. 

Pecten mediacostatus Hanna__. 

Pecten subnodosus Sowerby___ 

Pecten deserti Conrad———_._. 

Cyathodonta, undulata Conrad. 

Encope tenuis Kew________-_.

Ostrea jacobaea Rochebrune.

Pecten subnodosus Sowerby. 

Pecten circularis Sowerby.

Encope grandis (L. Agassiz).

DESCRIPTIONS OF NEW SPECIES 

Ostrea tamiamiensis Mansfield, n. sp.

Plate 14, Figures 1, 3

Shell large, rather thin, nearly flat, orbicular, with 

fluted margins. Exterior surface of holotype partly 

concealed by matrix but reveals about six rather strong 

undulating radials. Hinge area rather narrow and 

furrowed with a rather narrow and shallow channel. 

Submargins with elongate corrugations. Muscle scar 

orbicular and situated slightly to the left of the center 

of left valve.

Dimensions: Holotype, left valve (catalogue No. 

371320, U. S. Nat. Mus.), length, 139 millimeters; 

height, 131 millimeters.

Type locality: Station 1/1177, Tamiami Trail, 5 

miles east of Carnestown and 7 miles northeast of 

Everglades, Collier County, Fla.

The closest related Recent species appears to be 

Ostrea jacobaea Rochebrune,16 a species occurring in 

the Gulf of California.

14 Hanna, G. D., Paleontology of Coyote Mountain, Imperial County, 

Calif. : California Acad. Sci. Proc., 4th ser., vol. 14, No. 18, pp. 427- 

502, 1926.

35 Woodring, W. P., Distribution and age of the marine Tertiary deposits of the Colorado Desert: Carnegie Inst. Washington Pub. 418, 

pp. 1-25 (especially p. 25), 1931.

16 Rochebrune, A. T. de, Mus. hist. nat. Paris Bull., vol. 1, p. 241, 

1895.

Occurrence: Pliocene. Station 1/1177 (type locality, 1 valve); station 1/1180 (1 valve); station 

1/1176 (1 valve); station 1/1179 (2 valves).

The specimens collected at stations 1/1179 and 

1/1176 are much smaller than those collected at stations 1/1177 and 1/1180 but have the same general outline and appear to belong to the same species.

Ostrea tamiamiensis monroensis Mansfield, n. subsp.

Plate 14, Figure 2; Plate 15, Figures 1-4

Shell rather thick and heavy, ovate, moderately 

convex, with fluted ventral margins in adult specimens. Exterior marked with rather sharp, subspinose 

ribs separated by deep and narrow valleys. Hinge 

area moderately wide and furrowed with a rather 

wide channel. Submargins with weak elongated 

crenulations. Muscle scar prominent and rounded in 

outline.

Dimensions: Cotypes (catalogue No. 371321, U. S. 

Nat. Mus.): Left valve, length, 89 millimeters; height, 

102 millimeters. Right valve, length, 76 millimeters; 

height, 96 millimeters.

Type locality: Station 1/1179, Tamiami Trail, 9 

miles west of Pinecrest, in sec. 13, T. 54 S., R. 32 E., 

Monroe County, Fla.

This new subspecies differs from O. tamiamiensis 

in having a heavier, more inflated, and less rounded 

shell.
PLIOCENE FOSSILS FROM LIMESTONE IN SOUTHERN FLORIDA 47

Ostrea scitlpturata Conrad has more prominent 

crenulations on the submargins and lower and more 

rounded ribs than the new subspecies.

Occurrence: Pliocene. Found only at the type 

locality.

Pecten (Nodipecten) pittieri collierensis Mansfield, n. subsp.

Plate 16, Figures 3, 5

Shell1 large, orbicular, moderately ventricose, equivalve, and nearly equilateral, the posterior region being slightly more produced. Sculptured with broad, 

nearly flat, weakly undulating ribs (seven on the left 

valve and eight on the right) separated by little 

wider interspaces. The ribs are broader over the middle of the disk and narrower on each side. Top of 

ribs sculptured with five to eight coarse, raised threads 

separated by narrower interspaces. Spaces between 

major ribs marked with three to five coarse, weakly 

undulating threads and occasionally with a finer 

thread. Submargins sculptured with six to eight 

radial threads, which are equal in strength to the intercostal threads. Ears ornamented with rather coarse 

radiating riblets.

Dimensions: Holotype (catalogue No, 371326, U. S. 

Nat. Mus.), left valve, length, 142 millimeters; height, 

125 millimeters. Para type, right valve (catalogue No. 

371327, U. S. Nat. Mus.), length, 100 millimeters; 

height, 104 millimeters.

Type locality: Station 1/1176, Tamiami Trail, 

about 11 miles east by north of Marco, Collier County, 

Fla.

The subspecies differs from Pecten (Nodipecten) 

pittieri Dall,17 a species collected from Moin Hill, 

near Port Limon, Costa Kica, horizon <z, in having 

a more ventricose shell which is ornamented with 

wider and fewer (by two) ribs. The surface of the 

ribs on the subspecies, although slightly corroded, 

does not distinctly indicate the vaulted scales, which 

are strongly developed on the left valve of P. pittieri. Dall, in his original description of P. pittieri, 

placed it in the section Lyropecten, but it appears to 

be more closely related to the section Nodipecten than 

to Lyropecten.

Pecten pittieri Dall and the new subspecies appear 

to be more closely related to Pecten (Nodipecten} 

nodosus Linnaeus, of the east coast, than to Pecten 

(Nodipecten) subnodosus Sowerby, of the west coast.

The new subspecies appears to be an intermediate 

form between Pecten pittieri and Pecten nodosus.

Pecten (Nodipecten) veatchii Gabb, a Pliocene 

species from Cerros Island, off Lower California, appears from the illustration to be closely related to 

my new subspecies.

17 Dall, W. H., New species of fossil shells from Panama and Costa 

Rica: Smithsonian Misc. Coll., vol. 59, No. 2, p. 10, 1912.

Occurrence: Pliocene. Station 1/1176 (type locality, 2 valves), station 1/1180 (paratype locality, 1 

valve), and station 1/1178 (2 valves).

Pecten (Lyropecten) tamiamiensis Mansfield, n. sp.

Plate 16, Figures 4, 6

Shell rather small, ovate, moderately ventricose, 

equivalve, and nearly equilateral. Both valves similarly sculptured. Bight valve sculptured with 23 

major ribs, which are stronger over the middle of the 

disk and weaker on the lateral areas. The two marginal posterior ribs are paired and much weaker than 

the others. Interspaces occupied by a single strong, 

rounded riblet. Surface of shell ornamented with 

fine concentric, beakward-reflected imbrications. Anterior ear with a rather deep byssal notch and externally marked with six rather coarse radials; posterior ear with finer radials than anterior.

Dimensions: Holotype (catalogue No. 371325,11. S. 

Nat. Mus.), length, 69 millimeters; height, 74 millimeters. One right valve with the margins broken off 

and occurring at the type locality is a little larger than 

the holotype, its length being 82 millimeters and height 

83 millimeters.

Type locality: Station 1/1178, Tamiami Trail, 6 

miles west of crossroads leading to Everglades, Collier 

County, Fla.

Pecten tnediacostatus Hanna,18 collected from "Alverson Canyon, on the south side of Coyote Mountain, 

Imperial County, Calif., in the Pliocene coral reef 

about midway up the canyon," apparently is the 

nearest related fossil species, but by a comparison 

made from the illustration, it appears to have a narrower shell with smaller ears than the new species.

Occurrence: Pliocene. Station 1/1178, type locality (3 valves), station 1/1179 (6 valves).

Pecten (Plagioctenium) evergladensis Mansfield, n. sp.

Plate 17, Figures 1, 2, 4, 5

Shell small, broadly orbicular, probably nearly equivalve, inequilateral, the posterior region being more 

produced. Bight valve of holotype inflated and swollen 

behind the umbo; posterior region more gently sloping to submargins than anterior; base broadly 

rounded. Sculptured with 22 nearly flat laterally 

sloping ribs separated by much narrower interspaces. 

Sides of ribs and submargins of shell marked with 

moderately coarse, nearly erect, concentric lamellae. 

Submargins without any distinct radials. Bight ear 

with a shallow byssal notch and ornamented with six 

radials; left ear bearing weak radials on the lower

18 Hanna, G. D., Paleontology of Coyote Mountain, Imperial County, 

Calif.: California Acad. Sci. Proc., 4tn ser., vol. 14, No. 18, p. 472, pi. 

22, fig. 6, pi. 24, fig. 2, 1926.
48 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1931

half. Left valve of immature and slightly corroded 

paratype sculptured with 20 ribs, which are a little 

lower than those on right valve; submargins without 

distinct radials.

Dimensions: Holotype, right valve (catalogue No. 

371323, U. S. Nat. Mus.), length, 58 millimeters; 

height, 52 millimeters. Paratype, left valve (catalogue No. 371324, U. S. Nat. Mus.), length, 29 millimeters; height, 28 millimeters.

Type locality: Station 1/1178, Tamiami Trail, 6 

miles west of crossroad leading to Everglades, Collier County.

The new species differs from Pecten gibbus gibbm 

Linnaeus in the absence of any distinct radials on 

the submargins and in having a much more inequilateral shell. In the latter feature it more closely resembles Pecten circularis Sowerby, a Recent species 

geographically ranging on the west coast from Monterey, Calif., to the Gulf of California and Paita, Peru. 

Pecten (Plagioctenium) comparilis Tuomey and 

Holmes, an upper Miocene species, appears to be the 

ancestral form of the new species. Pecten mendenhalli Arnold, a Pliocene species collected at Santa 

Rosalia, Lower California, and also occurring at Alverson Canyon, San Diego County, Calif., is nearly 

related to the new species.

Occurrence: Pliocene. Station 1/1178 (type locality, 2 valves), station 1/1177 (paratype locality, 3 

valves), station 1/1180 (5 valves), station 1/1176 (2 

valves), 1/1179 (4 valves).

Specimens occurring in the Caloosahatchee marl, 

Florida, have the same characteristics as the new 

species and appear to belong to it. The Caloosahatchee specimens appear to have been referred to P. 

gibbus gibbus Linnaeus by Dall,19 but they are unlike 

the Recent species referred to that variety.

Cassidulus (Rhynchopygus?) evergladensis Mansfield, n. sp.

Plate 18, Figures 1-10

Test large, suborbicular, and moderately high; upper surface convex and broadly rounded, the posterior 

surface more gently inclined than the anterior; lower 

surface nearly flat except in the area surrounding the 

peristome, where it is shallowly concave. Apical system, situated opposite the peristome, is rather large, 

granular, and slightly elevated; so far as revealed, a 

genital pore is at the juncture of the petals and a 

smaller radial pore is opposite each petal. Ambulacral areas petaloid at dorsal portions. Petals rather 

long, extending nearly to the ambitus, expanding to 

about one-third their length from the apical system, 

then gradually contracting distally, and nearly closing at their extremities; poriferous zones rather wide,

M Dall, W. H., Contributions to the Tertiary fauna of Florida: 

Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 745, 1898.

shallowly depressed; pores nearly equal in size and 

rounded in outline; pairs of pores conjugate. Interporiferous areas weakly tumid. Posterior interambulacrum weakly medially arched. Periproct rather 

large, longest transversely; supramarginal, the lower 

margin being about 4 millimeters above the ambitus; 

the upper arched margin slightly overhangs the 

aperture. Peristome excentric anteriorly, pentagonal, 

transversely elongate, and surrounded by a large welldefined floscelle with prominent bourrelets. The outer 

pores of the floscelle are more direct and more regularly placed; the inner ones are more irregularly 

placed and some of them are arranged in two rows. 

The surface of the test is closely set with scrobiculate 

tubercles.

Dimensions: Cotypes (catalogue No. 371329, U. S. 

Nat. Mus.): Larger slightly crushed cotype with preserved periproct, length, 73 millimeters; width, 74 

millimeters; height, 29 millimeters. Smaller cotype 

(posterior end broken off), width, 57 millimeters; 

height, 32 millimeters. Paratype (catalogue No. 

371330, U. S. Nat. Mus.), length, 75 millimeters (posterior end broken) ; width, 64 millimeters; height, 35 

millimeters.

Occurrence: Station 1/1177, Tamiami Trail, 5 miles 

east of Carnestown and about 7 miles northeast of 

Everglades, Collier County, Fla. (type locality); station 1/1179, Tamiami Trail, 9 miles west of Pinecrest 

(sec. 13, T. 54 S., R. 32 E.), Monroe County, Fla. 

(paratype locality). Near Moore Haven, Glades 

County, Fla.; probably dredged from the canal. Only 

one fairly well preserved specimen, which was embedded in limestone, has been collected near Moore 

Haven; it is in the collection of the Florida Geological 

Survey.

Cassidvlus evergladensis resembles, in a general way, 

the figured type of Cassidubus (Pygorhynchus) alah 

bamensis Twitchell,20 a species collected at the Natural 

Bridge, St. Stephens, Washington County, Ala., but the 

lower surface of the test of that species is more concave longitudinally, and the periproct is at a greater 

distance above the ambitus. The same authors 21 

refer the " St. Stephens limestone" (upper part) to 

the lower Oligocene.

Encope macrophora tamiamiensis Mansfield, n. subsp.

Plate 17, Figure 8

In the report by Cooke and Mossom 22 I referred 

this form to Encope 'macrophora Ravenel, but I now 

believe, after more study, that it represents a new subspecies of E. macrophora.

20 Clark, W. B., and Twitchell, M. W., The Mesozoic and Cenozoic 

Echinodermata of the United States: 13. S. Geol. Survey Mon. 54, p. 

172, pi. 80, figs. 3a-d, 1915.

21 Idem, p. 173.

22 Cooke, C. W., and Mossom, Stuart, Geology of Florida: Florida 

Geol. Survey Twentieth Ann. Kept., p. 156, 1929.
PLIOCENE FOSSILS FROM LIMESTONE IN SOUTHERN FLORIDA 49

E. ma&rophora tamiamiensis appears to be an intermediate form between E. macrophora and E. 

grandis (L. Agassiz). It differs from E. macrophora in having a proportionately wider and thinner 

test, a concave instead of convex posterior margin, and 

a much smaller interambulacral lunule. It differs 

from E. grandis, a Recent species reported by A. 

Agassiz 2* to occur in the Gulf of California, in having in general a shallower anterior marginal notch 

and less incised lateral marginal notches. The posterior margin on both forms is very similar in the 

degree of convexity, indicating a close relationship.

The test of the new subspecies is usually wider than 

long, rather thin, but not having sharp edges. The

23 Agassiz, Alexander, Revision of the Echini: Harvard Coll. Mus. 

Comp. Zoology Illus. Catalog, No. 7, pt. 3, p. 545, pi. 13d, figs. 5, 6, 

1873.

region directly in front of the lunule is the thickest 

part of the test. The lunule is elliptical and is surrounded on its upper surface by a raised border.

Dimensions: Holotype (catalogue No. 371328, U. S. 

Nat. Mus.), length, 84 millimeters; width, 87 millimeters; height, 11 millimeters; thickness of margins, 

about 6 millimeters.

Type locality: Station 1/1177, Tamiami Trail, 5 

miles east of Carnestown and about 7 miles northeast 

of Everglades, Collier County.

Occurrence: Pliocene. Type locality (abundant), 

station 1/1180 (abundant), station 1/1178 (rare?). 

Small specimens that have been referred to Encope 

macrophora, from the Pliocene Caloosahatchee marl 

at Alligator Creek, Monroe County, Fla., appear to 

be more closely related to the new subspecies than to 

E. macrophora.

PLATES 14-18

51
PLATE 14

FIGURES 1, 3. Ostrea tamiamiensis Mansfield, n. sp., holotype (p. 46). 

1. Exterior of left valve. 

3. Interior of same valve.

FIGURE 2. Ostrea tamiamiensis monroensis Mansfield, n. subsp., paratype, left valve, catalogue No. 371322, U. S. Nat. Mus. (p. 46). 

FIGURE 4. Turritella sp. aff. Turritella perattenuata Heilprin, catalogue No. 371319, U. S. Nat. Mus., figured specimen. Collected 

at station 1/1180, Tamiami Trail, Carnestown, 4 miles north of Everglades, Collier County, Fla. 

52
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PLIOCENE FOSSILS FROM LIMESTONE IN SOUTHERN FLORIDA
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PLIOCENE FOSSILS FROM LIMESTONE IN SOUTHERN FLORIDA
PLATE 15

FIGURES 1-4. Ostrea tamiamiensis monroensis Mansfield, n. subsp., cotypes (p. 46).

1. 3. Exterior and interior of right valve.

2. 4. Exterior and interior of left valve.

53
PLATE 16

FIGURE 1. Pecten subnodosus Sowerby. (After Hanna, California Acad. Sci. Proc., 4th ser., vol. 14, No. 18, pi. 25, fig. 6, 1926.) 

Hanna's figured specimen was collected in a branch of Alverson Canyon, at the base of Coyote Mountain, Imperial County, 

Calif. The photograph is used here for comparison with Figures 3 and 5 of this plate.

FIGURE 2. Pecten mediacostatw Hanna. (After Hanna, California Acad. Sci. Proc., 4th ser., vol. 14, No. 18, pi. 24, fig. 2, 1926.) 

The photograph, taken from the original, is that of the holotype, which was collected from " Alverson Canyon, on the south 

side of Coyote Mountain, Imperial County, Calif., in the Pliocene coral reef about midway up the canyon." The illustration 

is used here for comparison with Figures 4 and 6 on this plate. 

FIGURES 3, 5. Pecten (Nodipecteri) pittieri collierensis Mansfield, n. subsp. (p. 47). 

3. Paratype, right valve. 

5. Holotype, left valve.

FIGURES 4, 6. Pecten (Lyropecteri) tamiamiensis Mansfield, n. sp., holotype (p. 47). 

4. Left valve of specimen. 

6. Right valve of specimen. 

54
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Shows also, for comparison, specimens obtained elsewhere
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 170 PLATE 17

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Shows also, for comparison, specimens obtained elsewhere
PLATE 17

FIGURES 1, 2, 4, 5. Pecten (Plagioctenium) evergladensis Mansfield, n. subsp. (p. 47).

1. 4, 5. Holotype, right valve: 1, 4, Exterior and interior of same valve; 5, posterior submargin, showing the nearly smooth 

area.

2. Paratype, left valve. Collected at station 1/1177, Tamiami Trail, 5 miles east of Carnestown and about 7 miles northeast of Everglades, Collier County, Fla.

FIGURES 3, 6. Pecten (Lyropecteri) deserti Conrad, left valve, catalogue No. 324564, U. S. Nat. Mus. Collected at station 3919 

east end of Coyote Mountain, Imperial County, Calif., by Stephen Bowers, 1904. Illustrated for comparison with Figures 

1, 2, 4, 5 on this plate. 

FIGURE 7. Encope grandis (L. Agassiz), upper surface of test, catalogue No. 10013, U. S. Nat. Mus. Photograph of a specimen

collected at La Paz, Gulf of California. Illustrated for comparison with Figure 8 on this plate. 

FIGURE 8. Encope macrophora tomiamiensis Mansfield, n. subsp., holotype, upper surface of test (p. 48).

55
PLATE 18

FIGURES 1-10. Cassidulus (Rhynchopygusf) evergladensis Mansfield, n. sp. (p. 48).

1. Right lateral surface of test of smaller cotype.

2. Lower surface of test of smaller cotype.

3. Upper surface of test of smaller cotype.

4. Lower surface of test of paratype, catalogue No. 371330, U. S. Nat. Mus.

5. Diagrammatic view of the preserved part of the apical system, based on the paratype.

6. Left lateral surface of test of paratype.

7. Portion of the anterior ambulacrum on upper surface of paratype.

8. Part of the ambulacral pores around the peristome of paratype.

9. Lower surface of test of larger cotype. 

10. Posterior surface of test of larger cotype. 

56

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