Fossils from the 

Eutaw Formation 

Chattahoochee River 

Region, Alabama-Georgia

GEOLOGICAL SURVEY PROFESSIONAL PAPER 274-J
Fossils from the 

Eutaw Formation 

Chattahoochee River 

Region, Alabama-Georgia

By LLOYD WILLIAM STEPHENSON

A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

GEOLOGICAL SURVEY PROFESSIONAL PAPER 274-J

Descriptions and illustrations 

of Late Cretaceous pelecypods 

.and one ammonite

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1956
UNITED STATES DEPARTMENT OF THE INTERIOR 

Fred A. Seaton, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

For sale by the Superintendent of Documents, U. S. Government Printing Office 

Washington 25, D. C. - Price 70 cents (paper cover)
CONTENTS

Abstract-__________________________________________

Introduction.______________________________________

Stratigraphic setting.________________________________

Eutaw localities in east-central Alabama and adjacent 

parts of Georgia __________________________________

Chattahoochee River____________________________

Chattahoochee County, Ga., east of Chattahoochee 

River_ ______________________________________

Russell County, Ala., west of Chattahoochee River_ 

Macon County, Ala___ _________ _________________

The Eutaw fauna and its relationships.________________

Systematic descriptions^.-___________________________

Mollusca.. ______________________________________

Nuculidae_ ________________________________

Page

227

227

228

228

228

230

231

233

234

234

234

234

Systematic descriptions—Continued 

Mollus ca—C on tinued

Arcidae_ ___________---_--

Pteriidae_ _______________

Ostreidae_ _______________

Anomiidae. ________--__-_

Cardiidae_ _______________

Veneridae. _______________

Mactridae_ ________--__-_

Corbulidae__ _____________

Placenticeratidae_ _________

References. ______________________

Index_ __________________________

Page. 

235

237

238

242

242

243

244

244

247

248

249

ILLUSTRATIONS

[Plates follow page 250]

PLATE 38. Views of the Eutaw formation in the Chattahoochee region.

39. Nucula, Breviarca, and Protarca.

40. Breviarca, Trigonarca, Pseudoptera, and Ostrea.

41. Cardium (Trachycardium) , Gryphaea, Anomia, and Pseudoptera.

42. Ostrea cretacea Morton.

43. Ostrea (Lopha) and Exogyra.

44. Cymbophora, Caryocorbula, Legumen, and Placenticeras.

45. Corbula and Placenticeras.

Page

FIGURE 30. Sketch map of parts of Russell County, Ala. and Chattahoochee and Muskogee Counties, Ga., showing fossilbearing localities, ___________-_____________.____.___________________________-_______________.__-_.« 229

in

A SHORTER CONTRIBUTION TO GENERAL GEOLOGY

FOSSILS FROM THE EUTAW FORMATION, CHATTAHOOCHEE RIVER REGION,

ALABAMA-GEORGIA

By LLOYD WILLIAM STEPHENSON

ABSTRACT

The Eutaw formation in east-central Alabama and an adjacent 

area in west-central Georgia has yielded an assemblage of fossil 

mollusksj some of the species of which are restricted to that unit 

and are of value in determining the age and stratigraphic relationships of the Upper Cretaceous formations in the Chattahoochee River region. Several of the restricted species have close 

relatives in younger formations in the Atlantic and Gulf Coastal 

Plain. Representative species are described in this paper.

The Eutaw formation is estimated to be about 200 feet thick 

in the Chattahoochee River region; it consists mainly of more 

or less argillaceous and micaceous sand with interbedded layers 

of calcareous sandstone and concretions, but includes some important layers and lenses of shale. These sediments were deposited in relatively shallow marine offshore waters. As a conspicuous part of their faunal content, certain layers contain vast 

numbers of the shells of Ostrea cretacea Morton that are either 

scattered through the matrix or are so abundant in some beds 

as to form almost solid oyster reefs.

Of the 16 species and 1 variety described, 10 species and 

the variety are new. All are bivalves except one, which is an 

ammonite. The described species are:

Nucula prepercrassa Stephenson, n. sp. 

\*Protarca obliqua Stephenson

*Breviarca symmetros Stephenson, n. sp. 

\*Trigonarca inflata Stephenson, n. sp.

Pseudoptera securiformis Stephenson, n. sp. 

Ostrea (Lopha) ucheensis Stephenson, n. sp.

cretacea Morton 

Gryphaea wratheri Stephenson 

Exogyra upatoiensia Stephenso-i 

\*Anomia preolmstedi Stephenson, n. sp.

*Cardium (Trachycardium) ochilleanum Stephenson, n. sp. 

\*liequmen aff. L. carolinense (Corrad)

*Cymbophora ochilleana Stephenson, n. sp. 

]*Caryocorbulat veatchi Stephenson, n. sp. 

georgiana Stephenson, n. sp.

longa Stephenson, n. var. 

Placenticeras benningi Stephenson, n. sp.

Forms marked with an asterisk in the above list are either 

identical with, or closely allied to, species in the Snow Hill marl 

member of the Black Creek formation of North Carolina and 

South Carolina. Five species marked with a dagger have 

identical or closely related representatives in the Cusseta sand 

in the Chattahoochee River region. It may be accepted that the 

indicated species are ancestral to species occurring in the stratigraphically younger Snow Hill marl member and in the Cusseta 

sand.

The presence of Gryphaea wratheri in the upper part of the 

Eutaw formation affords satisfactory evidence that the formation 

is synchronous with the upper part of the Austin chalk of Texas, 

which includes a zone of G. wratheri. The accepted Santonian 

age of the upper part of the Austin chalk of Texas carries with it 

the implication that the Eutaw of the eastern Gulf region is also 

of Santonian age.

INTRODUCTION

The type area of the Eutaw formation is in the 

vicinity of Eutaw, the county seat of Greene County 

in west-central Alabama. As at present classified 

(Monroe, Conant, Eargle, 1946, p. 204-210), the 

Eutaw formation in central and western Alabama consists of 160 to 240 feet of marine sediments, including 

interbedded glauconitic sands and clays in its lower 

part and mainly massive glauconitic sand, the Tombigbee sand member, in its upper part. There is no sharp 

line of separation between these two parts. Fossils 

are rare in the lower part and common in the Tombigbee 

sand member, especially so in its upper part.

The Eutaw formation of west-central Alabama is unconformably underlain by the McShan formation ,which 

consists of about 200 feet of crossbedded, fine- to 

medium-grained marine sand that is characterized by 

its content of fine pale green, partly leached glauconite 

grains; this unit was formerly considered a part of the 

overlying Eutaw formation. The Eutaw formation of 

central and west-central Alabama is unconformably 

overlain by the Mooreville chalk, the lowermost formation of the Selma group of Alabama and Mississippi.

Traced eastward the McShan formation disappears 

not far west of the longitude of Montgomery, where 

presumably it is covered by a traiisgressive overlap of 

the Eutaw formation. From Montgomery County 

eastward the Eutaw formation appears at the surface 

in an easily traceable belt 4 to 12 miles wide to and beyond the Chattahoochee Kiver. Throughout this

227
228 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

distance the formation is uncorformably underlain by 

an undifferentiated unit of the Tuscaloosa group, 

presumably the Gordo formation. From Montgomery 

County eastward to the longitude of Hardaway in 

Macon County, the Eutaw formation is unconformably 

overlain by the Mooreville chalk of the Selma group; 

east of Hardaway to, and beyond, the Chattahoochee 

River the overlying unconformable unit is a more or 

less argillaceous and calcareous sand facies of the 

Mooreville unit, to which the name Blufftown formation 

has been given (Veatch, 1909, p. 82-90; Monroe, 1941, 

p. 73-88).

In its eastward extension from Montgomery County 

the Eutaw formation has not been satisfactorily 

divided into a lower and an upper part corresponding 

to the two parts recognized in central and western 

Alabama; there is some reason to believe that the lower 

part of the formation is wanting and that the beds that 

are present belong mainly to the Tombigbee sand member. In the Chattahoochee region fossiliferous zones 

occur at different stratigraphic positions in the formation 

from near its base to its top.

Selected localities that afford exposures of the Eutaw 

and associated formations in the Chattahoochee region 

were visited by Norman F. Sohl and me in March 1955, 

and supplementary collections of fossils were made. 

Through the courtesy of Maj. Gen. Joseph H. Harper 

and his subordinate officers, and especially by the personal guidance of Capt. J. F. Rast, we were able to visit 

several important localities in the Fort Benning Military 

Reservation.

The evolution of our knowledge of the Upper Cretaceous section of eastern Alabama is recorded in many 

papers, the more important of which are the following : 

T. A. Conrad (1860, p. 275-298); D. W. Langdon (1890, 

p. 587-606); S. W. McCallie (1903, p. 199-202); Otto 

Veatch (1909, esp. p. 82-106); L. W. Stephenson (1911, 

p. 66-215); L. W. Stephenson (1914, 77 p.); L. W. 

Stephenson and W. H. Monroe (1938, p. 1639-1657); 

Monroe (1941, 150 p.); Monroe (1947, p. 1817-1824); 

and D. H. Eargle (1950, preliminary map 105, with 

text).

STRATIGRAPHIC SETTING

The Eutaw formation of eastern Alabama and western 

Georgia has not been studied in detail. However, 

sections have been examined and fossils collected at 

localities along the belt of outcrop and the contacts 

of the unit with underlying and overlying formations 

have been seen at several places. The unit is unconformably underlain by sediments considered by Monroe 

(1947, p. 1,820) to be the eastward continuation of the 

Gordo formation of the Tuscaloosa group, and is unconformably overlain by the Mooreville chalk (of the

Selma group) and by the Blufftown formation, an 

eastern sand and clay facies of the Mooreville chalk.

Although the boundaries of the Eutaw formation in 

Macon and Russell Counties, Ala. and in Chattahoochee 

County, Ga., have not been mapped in detail the 

approximate belt of outcrop in the Alabama counties 

is shown on a map prepared by Monroe (1941, pi. 1) 

and the important localities on Chattahoochee River 

and in Chattahoochee County, Ga., are shown on an 

accompanying sketch map (fig. 30).

The Eutaw formation is estimated to be about 200 

feet thick in the Chattahoochee River Valley where it 

is divisible into two parts that do not correspond to 

the two parts recognized in central and western Alabama. The lower part consists mainly of 130 feet or 

more of massive marine sand, indurated in certain 

layers, and containing in some layers vast numbers of 

the shells of Ostrea cretacea Morton. For convenience 

of reference this part of the formation is here designated the 0. cretacea zone. This zone is believed to be 

approximately synchronous with the Tombigbee sand 

member of the Eutaw formation of central and western 

Alabama. The upper part of the formation is greenishgray somewhat laminated clay with subordinate sand, 

probably attaining a thickness of 50 or more feet; the 

best exposure of this clay section is at Slick Bluff on 

Chattahoochee River 2 miles southeast of Fort Mitchell, 

Russell County. The clay contains the imprints of 

fossils. Whether this clay forms a persistent unit in 

the upper part of the Tombigbee sand member, or is 

present only as one or more lenses of local extent, has 

not been determined. However, the clay is recognizable above the 0. cretacea zone for at least 7 or 8 miles 

west of the exposures on Chattahoochee River (see 

p. 232). This clay unit may be stratigraphically a little 

higher and younger than the main body of the Tombigbee sand in central and western Alabama where presumably it is overlapped and concealed by the transgressing Mooreville chalk.

EUTAW LOCALITIES IN EAST-CENTRAL ALABAMA AND 

ADJACENT PARTS OF GEORGIA

Descriptions of a few selected localities in Macon 

and Russell Counties, Ala., and in Chattahoochee 

County, Ga., that show the character and stratigraphic 

relationships of the Eutaw formation, and the zonal 

distribution of its fossils, are given below.

CHATTAHOOCHEE RIVER

Outcrops in the bluffs and banks of Chattahoochee 

River, where the belt of outcrop of the Eutaw formation intersects that stream, reveal the character of the 

strata forming the basal 28 and the upper 50 feet or 

more of the formation; some of the intervening beds
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 229

85°05'

Base from maps of Seale, Ala.-Ga , and Columbus, Ga -Ala , 

scale 1 62 500, by Army Map Service, 1945-1950

FIGURE 30.—Sketch map of parts of Kussell County, Ala. and Muskogee and Chattahoochee Counties, Ga., showing fossil-bearing localities. Numbers are the collection 

numbers of the United States Geological Survey; each collection made at a given locality bears a separate collection number.

appear in small exposures in the river banks. The 

first exposure of the formation is in a low bluff on the 

Georgia side below the mouth of Upatoi Creek, 8.5 

miles by the river below Columbus, and the last exposure is in a bluff on the Alabama side, 200 yards above 

the mouth of Uchee Creek, 16.5 miles below Columbus. 

An account of these exposures has been given by 

Stephenson (1911, p. 82, 83, 117-121). In present 

usage the Eutaw formation is restricted to the strata 

•exposed along the river between the points indicated 

in the preceding paragraph.

Between the mouth of Uchee Creek and Chimney 

Bluff on the east side of the river 22 miles below 

Columbus no exposures that show the contact between 

the Eutaw and overlying Blufftown formations were 

observed. The lower 25 feet of strata exposed at 

Chimney Bluff consists of irregularly bedded, crossbedded lignitic sand and clay that is interpreted to be 

referable to the lower part of the Blufftown formation.

The most important Eutaw fossil-bearing strata exposed along the river are those at Broken Arrow Bend, 

old Burdock Landing, and Slick Bluff. The strata com-
230 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

posing the Eutaw formation in the Chattahoochee area 

dip gently to the south at an inclination probably not 

exceeding 30 or 35 feet to the mile.

Section at Broken Arrow Send.—At Broken Arrow 

Bend about 10 miles by the river (airline 6 miles) 

downstream from Columbus, Ga., exposures along the 

right and left banks of Chattahoochee River show that 

the contact of the Eutaw formation with the underlying Gordo formation of the Tuscaloosa group is a 

broadly undulating unconformity. The Gordo consists of coarse, compact, crossbedded, arkosic and 

micaceous sand and interbedded light-drab to almost 

white clay. The thickness above water level as seen 

along the left bank at a medium low stage of the river 

is 4 or 5 feet and the upper eroded surface rises and falls 

through a vertical range of 5 feet or more, in places 

passing below water level and reappearing again farther 

downstream. The basal 2 to 8 feet or more of the overlying Eutaw formation consists of medium to coarse 

crossbedded sand and interbedded laminated clay. 

These materials contain lignitized and silicified wood, 

including large logs, and poorly preserved fossil leaves. 

These basal beds are conformably overlain by 15 feet 

or more of slightly laminated gray micaceous, calcareous sand and claj^ including interbedded layers of 

calcareous concretionary nodules 2 or 3 feet apart; these 

beds dip gently downstream.

The calcareous beds at Broken Arrow Bend contain 

a late Cretaceous marine fauna, the species of which 

have been only partly identified and described. Among 

the forms present are: Pseudoptera securiformis Stephenson, Ostrea cretacea Morton, Exogyra upatoiensis 

Stephenson, Anomia preolmstedi Stephenson, Legumen 

cf. L. carolinensis (Conrad), Caryocorbulal veatchi 

Stephenson and Placenticeras benningi Stephenson 

(USGS colls. 847, 5384, 6409).

Half a mile downstream from Broken Arrow Bend 

the layers of nodular limestone dip down to water 

level and between two of these indurated beds is a 

layer made up largely of the shells of Ostrea cretacea 

Morton (large variety) (USGS 5385). From here 

downstream for the next 2 miles a few low outcrops in 

the river banks reveal the gently southward dipping 

indurated beds that characterize the zone of 0. cretacea, 

which is estimated to be between 75 and 100 feet thick 

in this area. More complete exposures of the 0. cretacea 

zone, as it is developed west of Chattahoochee River in 

Russell and Macon Counties, Ala., are described on 

following pages.

Section at old Burdock Landing.—The upstream end 

of Uchee Shoals (or Rapids) is at a point on the river 

about east of Fort Mitchell, and the shoals extend from 

there for several miles down the river. The submerged

indurated layers of the Ostrea cretacea zone of the Eutaw 

formation are the cause of the shoals. The site of old 

Burdock Landing is on the Alabama side about threefourths of a mile below the upstream end of the shoals. 

An exposure just below the landing reveals 30 feet of 

greenish-gray clay, laminated in part, with fine sand 

partings. From a fossiliferous bed at the water's edge 

a short distance below the landing the following forms 

are identified: Pseudoptera securiformis Stephenson, 

Ostrea cretacea Morton, 0. (Lopha) ucheensis Stephenson, Anomia preolmstedi Stephenson, Cyprimeria cf. C. 

depressa Conrad, Legumen aff L. carolinense (Conrad), 

and Caryocorbulal georgiana Stephenson? (USGS colls. 

848 and 5386). These fossils are mainly in the form of 

prints in finely micaceous clay, but 0. cretacea Morton 

is preserved as shells in dark-gray argillaceous, finely 

micaceous sand.

Section at Slick Bluff.—Slick Bluff is half a mile 

downstream from old Burdock Landing. The bluff 

exposes greenish-gray clay that has been considerably 

disturbed by relatively recent landslides and at some 

earlier time was affected by earth movements that 

produced sand-filled fissures, now appearing as socalled sandstone dikes; these dikes were first described 

by S. W. McCallie (1903, p. 199-202). On account of 

the disturbed condition of the clay, the section could 

not be measured but the thickness was estimated to 

be 50 feet or more. A few fossil prints were collected 

from the disturbed clay among which were recognized: 

Ostrea ucheensis Stephenson, Cyprimeria cf. C. depressa 

Conrad, Legumen aff. L. carolinensis (Conrad), and 

Caryocorbula? georgiana Stephenson? (USGS colls 845, 

5387). The clay section at Slick Bluff overlies the 

calcareous beds (=0. cretacea zone) and forms the 

upper part of the Eutaw formation as here interpreted.

Section near mouth of Uchee Creek.—Cretaceous 

sedimentary rocks interpreted to lie close to the uppermost part of the Eutaw formation are exposed in the 

right bank of the river about 200 feet upstream from the 

mouth of Uchee Creek. These beds consist of 25 feet 

of thinly laminated sand and clay with seams of finely 

comminuted vegetable matter; the sand is white or 

stained yellow and is very fine and micaceous; the clay 

is dark gray. The Cretaceous beds are unconformably 

overlain by 10 feet of terrace gravel, sand, and loam 

(Pleistocene).

CHATTAHOOCHEE COUNTY, GA., EAST OF 

CHATTAHOOCHEE RIVER

Section on Upatoi Creek.—A bluff on Upatoi Creek 

7 miles southeast of Columbus, Ga., formerly (1908) 

exposed the section described below; the section is 

now largely concealed by vegetation.
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 231

Section on Upatoi Creek one-fourth mile below the old ColumbusCusseta road crossing, 7 miles southeast of Columbus

Eutaw formation: Feet 

Sand, marine, weathered brown, unconsolidated___ 5 

Sand, fine, and clay, partly weathered, greenishgray, irregularly foliated___..__________________ 5

Sandstone, fine-grained, white.._________________ 1

Sand, fine, and clay, greenish-gray, irregularly 

foliated-____________________________________ 2

Sand, argillaceous, dark greenish-gray ____________ 5

Sandstone, fine-grained, white___________________ iy2

Clay, with irregular dark clay foliations, and lignite 

fragments; includes discontinuous nodular limestone layers and irregularly distributed calcareous 

concretions; fossiliferous______________________ 25

Unconformity, contact poorly exposed. 

Tuscaloosa group (Gordo formation):

Sand, coarse, arkosic, crossbedd.ed, light-gray 

streaked with yellow; includes subordinate layers 

of sandy clay_--_____________________________ 22

Concealed to water leveL_______________________ 21 ±

Fossils described in this paper from the basal 25 feet 

of the Eutaw formation at the preceding locality are 

listed below.

Fossils from the basal 25 feet of the Eutaw formation on Upatoi 

Creek, 7 miles southeast of Columbus, Ga. (USOS 5373 and 

5S77)

Pseudoptera securiformis Stephenson 

Ostrea cretacea Morton 

Exogyra upatoiensis Stephenson 

Legumen aff. L. carolinense (Conrad) 

Placenticeras benningi Stephenson

Additional fossils, mostly poorly preserved, belonging 

to the following genera, have been identified from the 

Upatoi Creek locality: Trigonarca, Pholadomya, Cardium, Tellina?, Turritella, Anchura, and Volutomorpha. 

Several species of shark teeth are present.

Section on Ochillee Creek.—Strata corresponding to 

the basal 25 feet of the Eutaw formation in the section 

on Upatoi Creek are exposed on Ochillee Creek at and 

near the site of the dam and the old mill at Ochillee, 

Chattahoochee County, and for several hundred yards 

both downstream and upstream from the dam site. 

The bridge of the present roadway is approximately at 

the site of the dam and mill. These beds are fossiliferous and include some fossils that are in a more complete 

state of preservation than those found at other Eutaw 

localities in the Chattahoochee area. A list of the 

species described from Ochillee Creek is given below.

Fossils from the basal 20-25 feet of the'Eutaw formation on Ochillee 

Creek near old Ochillee, ChattahoocheejCounty (USGS 5874, 5378,. 

15501, and 25570)

Protarca obliqua Stephenson

Pseudoptera securiformis Stephenson

Ostrea cretacea Morton

Anomia preolmstedi Stephenson

Legumen aff. L. carolinense (Conrad)

Cymbophora ochilleana Stephenson

Caryocorbula? veatchi Stephenson

Placenticeras benningi Stephenson

In addition to the species formally described in this 

paper, fossils belonging to the following genera have 

been recognized in the collections from Ochillee: Serpula 

(tubes), Idonearca, Pecten (Camptonectes*), Etea, Cyprimeria, Leptosolen, Turritella, and Anchura.

Both the dam and the water mill of former years 

have completely disappeared from the Ochillee locality. 

Upstream from the site of the dam there is now exposed 

in the bed of the creek marine argillaceous sand with 

irregularly distributed ovate concretions 4 to 8 inches 

in diameter; these concretions contain imprints and 

molds of fossils with films of adhering shell substance,, 

among which are many individuals of Pseudoptera 

securiformis Stephenson and Placenticeras benningi 

Stephenson (USGS 25570).

RUSSELL COUNTY, ALA., WEST OF CHATTAHOOCHEE

RIVER

Section 4 miles southwest of Phenix City.—The unconformable contact between the Gordo formation of the 

Tuscaloosa group and the overlying Eutaw formation 

was formerly well exposed on the old Columbus-Seale 

road 4 miles southwest of Phenix City (opposite Columbus) ; at this locality the contact is gently and broadly 

undulating. This locality was described in earlier 

papers (Stephenson, 1911, p. 74, 75, pi. Q-B; 1914, 

p. 10, 11, pi. l-B}. The Gordo formation of this paper 

is the same as the Lower Cretaceous of the earlier 

papers. The earlier correlation of this unit with the 

Lower Cretaceous seemed to have found partial confirmation in E. W. Berry's interpretation (oral communication) of a meager, poorly preserved fossil flora 

found at old Fort Decatur in Macon County, Ala. 

(Stephenson, 1914, p. 12). Additional plant remains 

collected from the same place at a later date caused 

Berry (1923, p. 433-435) to change his mind and refer 

the plants to the Upper Cretaceous, a correlation that 

is in agreement with the conclusions of more recent 

investigators.
232 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Section southwest of Youngs Bridge.—An exposure in 

a cut of U. S. Highway 431, on the northeastwardfacing slope of Uchee Creek valley 0.6 mile southwest 

of Youngs Bridge, reveals the following section:

Section in cut of U. S. Highway 4^1, on the northeastward-facing 

slope of Uchee Creek valley in SW}iNW}i sec. 26, T. 16 N., 

R. 29 E., Russell County, Ala.

Eutaw format'on: Feet 

Shale, gray, marine, with interbedded thin layers of 

light-gray sandstone in upper 15 feet, cut by 2 nearly 

vertical sandstone dikes; a soft sandstone bed about 

18 feet above base contains Inoceramus sp., Liopistha sp., and Placenticeras benningi Stephenson? 

(USGS 25462)_________________________________ 30

Sandstone, calcareous; contains many shells of Ostrea 

cretacea Morton________________________________ 1±

31 ±

The 30 feet of shale in the preceding section corresponds to part of the shale unit exposed at old Burdock 

Landing and in Slick Bluff on Chattahoochee River. 

The indurated fossiliferous bed at the base of the section 

marks the top of the 0. cretacea zone in this area.

Sections near Uchee.—A section in a cut on the new 

Hurtsboro-Marvyn highway, 5.9 miles south of Lee 

County line, about 2.6 miles southwest of Uchee, in 

northwestern Russell County, is as follows:

Section in cut on Hurtsboro-Marvyn highway, 5.9 miles south of 

Lee County line, in NE}iNE}i sec. 35, T. 16 N., R. 26 E., 

Russell County, Ala.

Bluff town formation: Feet 

Clay, greenish-gray, sandy, marine, with a lens of sand 

about 2.5 feet thick 8 feet below top ______________ 30

Sand, greenish-gray massive, marine, with two interbedded whitish indurated layers, about.___________ 4

Conglomeratic sand; includes quartz and phosphatic 

pebbles, many fragments of dark bones, and waterworn shells; also many medium-sized shells of a 

smooth Exogyra, and some large shells of Trigonarca, 

Cardium, and other forms ________________________ 1

Unconformity. 

Eutaw formation:

Sand, gray compact argillaceous, micaceous __________ 5

Sand, darker gray than the preceding; contains many 

shell fragments, mainly in the upper half, and some 

well-preserved shells, mostly small but including a 

few of medium size; included among the fossils are: 

Trigonarca inflata Stephenson, Exogyra sp. (medium 

size, smooth), Cyprimeria sp. (small), and Caryocorbulal veatchi longa Stephenson__________________ 10

50

A cut 011 the same highway, 0.15 mile to the north 

(downslope) from the preceding cut, 5.75 miles south 

of Lee County line, reveals an 18-foot section of marine 

sand, clay, and marl. A layer of coquinalike marl 

4 to 6 feet above the base contains many shells of

Ostrea cretacea Morton and a few internal molds of 

Pseudoptera securiformis Stephenson. This bed is near 

the top of the 0. cretacea zone.

A section described in detail by W. H. Monroe, that 

reveals the greater part, if not all, of the 0. cretacea 

zone, is exposed along the Marvyn road 2% miles (airline) north by west of Uchee.

Section along the old Marvyn road 2% miles (airline) north by west 

of Uchee, near center of sec. 7, T. 16 N., R. 27 E., on northeastward-facing slope of a headwater branch of a small tributary of 

Uchee Creek, Russell County, Ala.

Bluff town formation(?): peei

20. Sand, light-red, chert and quartz grains as much 

as one-fourth inch long, subangular, poorly 

sorted; weathered to colluvium in upper part__ 23 

Eutaw formation:

19. Sand, red and gray, fine, with thin laminae of gray

clay ______________________________________ 5

18. Sand, gray and yellow, fine, clayey, ferruginous,

micaceous; contains prints of fossils___________ 5}^

17. Sand, light-brown, fine, much more clayey than 

overlying bed; contains many prints of fossils, 

those in lower 2 feet retaining some white 

calcium carbonate.__________________________ 4}£

16. Sandstone, hard, fine-grained; base and top slightly 

irregular; contains many shells of Ostrea cretacea 

Morton, and some of Anomia preolmstedi Stephenson- ____________________________________ 1

15. Sand, light-brown, clayey, like bed 17 above;

contains many shells of 0. cretacea----------.- 3

14. Sandstone, hard, light-brown; contains many

shells of 0. cretacea _________________________ 1

13. Limestone, sandy, light-brown: contains shells of 

0. cretacea and 0. ucheensis Stephenson (USGS 

17766)____________________________________ 3

12. Limestone, sandy, hard, fine-grained____________ 1

11. Clay, indurated, light-tan or buff; contains many 

shells of 0. cretacea and some of Anomia preolmstedi Stephenson_ __________________________ 2}i

10. Sand, light-yellow, fine, micaceous, glauconitic(?)_ 1 

9. Clay (or silt), finely sandy, like bed 10; lower part 

contains large masses of chalklike precipitated 

calcium carbonate; contains many shells of 0. 

cretacea ______________________-__--------__ 11

8. Limestone, finely sandy, light-brown, largely composed of shells of 0. cretacea----------------- }i

7. Sand, light-brown, clayey; contains many shells

of 0. cretacea-.----------------------------- 3

6. Clay, blocky, light brownish-gray, with much 

chalklike precipitated calcium carbonate; some 

shells of 0. cretacea------------------------- 5

5. Bed composed mainly of 0. cretacea shells and a 

few shells of Anomia sp., with a matrix of lightbrown, very fine sandy clay _________________ 4

4. Chalk, light-buff and white, in silt or clay_ ______ 3

3. Boulders of hard crystalline limestone filled with 

shells of 0. cretacea; Anomia preolmstedi present; 

softer beds incompletely exposed in ditch but 

relationship to limestone not clear; many oyster 

shells appear waterworn (USGS 17776) _______ 12
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 233

Section along the old Marvyn road 2% miles (airline) north by west 

of Uchee, near center of sec. 7, T. 16 N., R. 27 E., on northeastward-facing slope of a headwater branch rf a small tributary of 

Uchee Creek, Russell County, Ala.—Continued

Eutaw formation—Continued Feet 

2. Sand, clayey, light-brown, soft, and white chalk, 

containing many shells of O. cretacea, alternating 

with light-brown chalky clay, merging downward into bed below._______________________ 43

1. Clay, finely sandy, blocky, light-brown and white 

chalk; contains shells of O. cretacea and prints of 

pelecypods; this bed is slightly more sandy in 

lower 15 feet_____________________________ 36

Concealed to water level of creek__________________ 14

182

In the preceding section layers 17-19 compose a 

sandy fades probably representing part of the clay unit 

of the. Eutaw formation exposed at Slick Bluff on 

Chattahoochee River. Ostrea cretacea Morton is recorded as ranging through a thickness of 130 feet of the 

section (layers 1—16). The new oyster, 0. ucheensis 

Stephenson, is listed in layer 13, where it is associated 

with 0. cretacea; this is 20 feet below the top of the 

Eutaw part of the section. Another lot of fossils from 

this locality (USGS 17585), recorded as obtained from 

the upper 20 feet of the 0. cretacea zone, includes 0. 

cretacea and 0. ucheensis. The new species, Pseudoptera 

securiformis Stephenson (USGS 17211) was obtained 

near the top of the 0. cretacea zone at this locality.

MAC ON COUNTY, ALA.

Section north of Creek Stand.—The zone of Ostrea 

cretacea Morton, which is at least 130 feet thick in 

northwestern Russell County, continues westward in 

comparable thickness into Macon County. A section 

similar, though less complete than the one described by 

Monroe 1% miles north by west of Uchee, is exposed on 

the Society Hill road 4.1 miles north by west of Creek 

"Stand.

Section on Society Hill road, northward-facing slope of Opintlocco 

Creek valley about 4-1 miles (airline) north by west of Creek Stand, 

Macon County, Ala.

formation:

7. Sand, massive, greenish-gray, argillaceous, calcareous, partly indurated to calcareous concretionary 

layers that form projecting ledges on the slope; 

contains vast numbers of the shells of Ostrea cretacea Morton, more abundant in some layers than 

in others (USGS 17007); a few shells of Gryphaea 

wratheri Stephenson present in an indurated 

layer 10 feet below crest of hill (USGS 18312) _ _ _ _ 40

6. Sand, soft, light-greenish-gray, calcareous.________ 14

Feet

Section on Society Hill road, northward-facing slope of Opintlocco 

Creek valley about 4-1 miles (airline) north by west of Creek Stand, 

Macon County, Ala.—Continued

Eutaw formation—Continued Feet 

5. Sand, dark-greenish-gray argillaceous, calcareous, 

glauconitic, partly indurated to nodular calcareous 

masses in upper 4 or 5 feet______-__________-_-- 9

4. Sandstone, concretionary, argillaceous, calcareous__ 1 

3. Clay, greenish-gray, calcareous__________________ 4^_

2. Sand, partly indurated, greenish-gray, calcareous,

with a few shells of O. cretacea Morton __________ }z

1. Sand, greenish-gray, argillaceous, calcareous, ______ 4

73

Neither the base nor the top of the Eutaw formation 

is exposed in the preceding section. However, the base 

is probably not more than a few feet below the surface 

at the crossing of the Society Hill road over Opintlocco 

Creek. The top of the section is near the crest of the 

slope overlooking the valley of Opintlocco Creek to the 

north.

A cut in the Society Hill road 0.85 mile south of the 

crest of the slope, 3.35 miles north of Creek Stand, 

exposes 15 feet of greenish-gray argillaceous sand with 

one indurated layer midway of the section. Oyster 

shells, apparently a large variety of Ostrea cretacea 

Morton, are abundant below and above the indurated 

layer. Assuming a uniform low dip of the Eutaw 

strata to the south, this oyster-bearing zone is stratigraphically a few feet higher than the topmost stratum 

of the section 4.1 miles north by west of Creek Stand. 

The contact of the Eutaw formation with the overlying 

Blufftown formation should intersect the road somewhere within the next 1 or 2 miles south of the cut.

The stratigraphic range of Ostrea cretacea in eastern 

Macon County as revealed in the preceding section, is 

at least 75 feet. The presence of Gryphaea wratheri 

Stephenson in the upper part of the section is consistent 

with its known occurrences elsewhere in eastern Alabama.

Section east by north of Hardaway.—The contact 

between the Eutaw formation and the overlying 

Blufftown formation is clearly revealed in an outcrop 

on a country road about 3.5 miles east by north of 

Hardaway station. 

Section in cut on country road, 3.5 miles east by north of Hardaway

station in NW}i sec. 7, T. 15 N., R. E., Macon

County, Ala.

Blufftown formation (lateral merging facies from Mooreville 

chalk): Feet 

Sand, strongly chalky, argillaceous___________________ 9

Conglomerate, including phosphatized molds of mollusks and many large pebbles of phosphatized limestone (as much as 6 inches long) with attached shells 

of Exogyra, Gryphaea, and Plicatula-- _______________ 1-2
234 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Section in cut on country road, 3.5 miles east by north of Hardaway 

station in NW/* 1 sec. 7, T. 15 N., R. 23 E., Macon 

County, Ala.—Continued

Unconformity.

Eutaw formation:

Sand, greenish-gray, fine, micaceous, with many small 

irregular concretionary masses in the form of nodules; 

one indurated bed 1 foot thick is 5.5 feet below the 

contact and another 1 foot thick is 8.5 feet below 

the contact; the sand contains Ostrea cretacea Morton, 

Gryphaea wratheri Stephenson, and Exogyra sp_ ______ 11

22

THE EUTAW FAUNA AND ITS RELATIONSHIPS

The fauna described in this paper includes most of the 

present available species in the Eutaw formation of 

east-central Alabama and an adjacent area in Georgia, 

that are well preserved or that have a useful significance 

in determining the stratigraphic position and relationships of the formation. It does not include many 

poorly preserved or rare fossils that, in our present 

knowledge, have no such significance. It may be 

safely assumed that thorough collecting at all available 

localities in the area would result in the discovery 

of additional new species and better preserved examples 

of described species based on incomplete material.

A list of the species, all mollusks, described in this 

paper is given below. Those marked with an asterisk^), 61 percent of the whole, are identical with, or 

closely allied to, species in the Snow Hill marl member 

of the Black Creek formation of North Carolina and 

South Carolina. It may be assumed from this relationship that many of the species in the Snow Hill faunal 

assemblage have their progenitors in the fauna of the 

Eutaw formation. The species in the list marked with 

a dagger(f) are identical with or closely related to 

species in the Cusseta sand in the Chattahoochee region, 

and may be regarded as ancestral to the Cusseta 

species. The Cusseta sand is interpreted to be approximately synchronous with the Snow Hill marl 

member.

List of fossils described in this paper

Nucula prepercrassa Stephenson, n. sp. 

f *Protarca obliqua Stephenson

Breviarca subinflata Stephenson, n. sp. 

symmetros Stephenson, n. sp. 

sp 

\*Trigonarca inflata Stephenson, n. sp.

Pseudoptera securiformis Stephenson, n. sp. 

Ostrea (Lopha) ucheensis Stephenson, n. sp.

cretacea Morton 

Gryphaea wratheri Stephenson 

Exogyra upatoiensis Stephenson 

\*Anomia preolmstedi Stephenson, n. sp.

*Cardium (Trachycardium) ochilleanum Stephenson, n. sp. 

\*Legumen aff. L. carolinense (Conrad)

*Cymbophora ochilleana Stephenson, n. sp.

]*Caryocorbula? veatchi Stephenson, n. sp.

* veatchi longa Stephenson, n. var.

* georgiana Stephenson, n. sp. 

Placenticeras benningi Stephenson, n. sp.

In Alabama, Gryphaea wratheri Stephenson occurs 

in the upper 35 or 40 feet of the Eutaw formation 

and also in the basal bed of the Mooreville chalk, where 

it may be in part indigenous and in part reworked from 

the Eutaw below. In eastern Alabama a few examples 

of the species have been found high enough in the lower 

half of the Mooreville chalk to indicate that they are 

indigenous there, and not reworked from the Eutaw. 

The thickness of the beds through which the species 

ranges has not been accurately determined, but it may 

not exceed 50 feet.

Gryphaea wratheri is an important' index fossil in 

fixing the stratigraphic position of the Eutaw formation 

and of the Mooreville chalk and its clay and sand facies, 

the Blufftown formation. In Texas the species ranges 

through a zone within the upper half of the Austin 

chalk that is not known to exceed 35 feet in thickness- 

(Stephenson, 1936, p. 1-4). The 0. wratheri zone is 

there underlain by the Inoceramus undulatoplicatus 

zone, which also lies within the upper half of the 

Austin chalk. Above the G. wratheri zone are three 

narrowly restricted zones, in succession the zones of 

Exogyra tigrina, Ostrea centerensis, and 0. travisana, 

the latter at the top of the Austin chalk. It is generally 

accepted that, in terms of European nomenclature, 

about the upper half of the Austin is of Santonian age. 

It follows that, on the indirect evidence afforded by 

G. wratheri, the upper part of the Eutaw formation 

and the overlying Mooreville and Blufftown formations r 

are of Santonian age.

SYSTEMATIC DESCRIPTIONS

Phylum MOLLUSCA

Class PELECYPODA

Order PRIONODESMACEA

Superfamily NUCULACEA

Family NUCULIDAE

Genus NUCULA Lamarck, 1799

Nucula prepercrassa Stephenson, n. sp.

Plate 39, figures 1-5

Adult shell of medium size, relatively thin, moderately inflated, elongate, inequilateral, equivalve; greatest inflation above the midheight and a little anterior 

to the midlength, from which point the surface rounds 

broadly over to the beak and broadly down to the ventral margin. Beaks prominent, incurved, opisthogyrate, approximate, situated about 0.7 of the length from 

the anterior extremity. Escutcheon broad, relatively 

short, broadly excavated. Lunule long, narrow, weakly
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 235

outlined. Anterodorsal margin long, very broadly 

arched, descending; anterior margin narrowly rounded; 

ventral margin long, broadly rounded; posterior margin 

subpointed; posterodorsal margin nearly straight, 

steeply descending. Surface with fine, weak concentric 

ridges, and with inconspicuous, low, flat, closely 

crowded, radiating ribs.

Dimensions of the holotype, a right valve: Length 30 

mm, height 20 mm, convexity 8 mm.

Hinge taxodont, teeth numerous, sharp, in two unequal series; in the anterior series the teeth number 30 

or more and in the posterior series about 12. In one 

paratype, a left valve, a poorly preserved large tooth, 

oblique forward, is present just back of the deeply impressed resilifer; this tooth fits into a corresponding 

socket, which is well preserved in the holotype, a right 

valve. In the holotype, a deeply submerged spoonshaped chondrophore projecting obliquely inward and 

forward provides a support for the resilium. Adductor 

scars small, subovate, slightly sunken, high in the shell; 

pallial line entire. Inner margin finely crenulate.

The few available specimens indicate that this species 

is similar in form and outline to Nucula percmssa 

Conrad, from the Owl Creek formation of Mississippi. 

It differs from Conrad's species in that the shell is much 

thinner, the hinge is narrower, the chondrophore is 

larger and projects farther inward, and the adult shells 

lack the senile inbending of the ventral margins so conspicuously developed in most of the Owl Creek shells; 

the latter feature in the Owl Creek shells may be a 

premature senile variation brought about by some inhibiting environmental condition, for some large adult 

shells in both the Owl Creek and the Klpley formation, 

that have been referred to Conrad's species, lack the 

inbending.

Types.—Holotype, from Ochillee Creek near Ochillee, Chattahoochee County, Ga., USGS 15501, TJSNM 125058; 1 figured 

paratype, same source, TJSNM 125059; 3 unfigured paratypes, 

same source, USNM 125060; 1 figured paratype, same source, 

USGS 5378, USNM 125061.

Distribution and range.—The species is known only from the 

lower part of the Eutaw formation at the type locality.

Superfamily ARCACEA

Family ARCIDAE

Genus PROTARCA Stephenson, 1923

Protarca obliqua Stephenson

Plate 39, figures 9-14

1923. Protarca obliqua Stephenson, N. C. Geol. and Econ.

Survey, v. 5, p. 104, pi. 19, figs. 1-3. 

1945. Protarca obliqua Stephenson. Nicol, Jour. Paleontology,

v. 19, no. 6, p. 619. 

1950. Protarca obliqua Stephenson. Nicol, Jour. Paleontology.

v. 24, no. 1, p. 92, pi. 21, fig. 10.

1954. Protarca obliqua Stephenson. Nicol, Jour. Paleontology, 

v. 28, no. 1, p. 98.

The genus Protarca and its type species, P. obliqua, 

from the Snow Hill marl member of the Black Creek 

formation, of North Carolina, were described by 

Stephenson (1923, p. 103-105, pi. 19, figs. 1-3), and 

descriptions of two smaller specimens from Ochillee 

Creek at old Ochillee, Chattahoochee County, Ga. 

were given in the same paper. Two other mediumsized specimens from Ochillee Creek and one juvenile 

shell from the upper part of the Eutaw formation in 

western Russell County, Ala., have since been added 

to the collection. Also the largest known example of 

the species was recently collected from a calcareous 

concretion in the Cusseta sand near Peachburg, Bullock 

County, Ala.; the Cusseta sand is approximately 

synchronous with the Snow Hill marl member.

Although the Ochillee material is from the lower 

part of the Exogyra ponderosa zone, and the type from 

the Snow Hill marl member is from the upper part of 

that zone, I am unable to recognize any essential 

differences that would justify a specific separation of 

the specimens from the two zones. In form, outline 

and internal features they seem to be identical; although 

the larger specimen from Ochillee (pi. 39, fig. 9) appears 

smooth as preserved, the small specimen (pi. 39, fig. 11) 

shows radial ribs well preserved all over its outer 

surface such as would probably be present on the 

young stage of the other shell from Ochillee Creek, were 

it well preserved in the umbonal region.

The specimen from the Cusseta sand near Peachburg, 

a left valve (pi. 39, figs. 13, 14), is larger and thicker 

than the holotype from the Snow Hill marl member 

of the Black Creek formation in North Carolina. This 

is the first record of Protarca obliqua in the Cusseta 

sand.

Types.—Holotype from Snow Hill marl member of Black 

Creek formation (upper part of Exogyra ponderosa zone), Snow 

Hill, Greene County, N. C., USGS 5348, USNM 31500; 1 plesiotype from the same zonal position, in the Cusseta sand, cut 

of Central of Georgia Railroad about 0.7 mile north of Peachburg, 

Bullock County, Ala., USGS 25478, USNM 125062; 2 plesiotypes 

from lower part of Eutaw formation (lower part of E. ponderosa 

zone), Ochillee Creek, Chattahoochee County, Ga., USGS 5378, 

USNM 125063; 1 plesiotype from the same source, USGS 

15501, USNM 125064; 1 unfigured example from the same 

source, USNM 125065.

Distribution.—In addition to the occurrences recorded in the 

preceding paragraph, one juvenile shell has been found in the 

upper part of the Eutaw formation in a cut on the HurtsboroMarvyn highway, 5.9 miles south of tha Lee County line, 

Russell County, Ala., USGS 25567, USNM 125066.

Range.—Assuming the correctness of the identifications indicated in this paper the known stratigraphic range of the species 

is throughout the Exogyra ponderosa zone and the geographic 

range is from eastern Alabama to eastern North Carolina, in the 

Atlantic and Gulf Coastal Plain.
236 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Genus BREVIARCA Conrad, 1872 

Breviarca subinflata Stephenson, n. sp.

Plate 39, figures 6-8

Shell small, thin, of medium inflation, subquadrate 

in outline, relatively short, subequilateral, equivalved 

except that the left valve slightly overlaps the right 

around the margin. Beaks prominent, strongly incurved, nearly direct, slightly separated, situated 

slightly anterior to the midleiigth. Umbonal ridge 

prominent, rounded 011 the crest, broadly humped and 

a little sinuous in the linear direction; posterodorsal 

slope steep; dorsal slopes broadly excavated adjacent 

to the hinge. Surface rounding down regularly from 

point of highest inflation to the anterior and ventral 

margins: surface with fine concentric and faint, fine 

radial lining.

Dimensions of the holotype, a left valve: Length 13 

mm, height 10.3 mm, convexity 4.4 mm.

Cardinal area amphidetic, elongate-subtrigonal; a 

central amphidetic, triangular ligamental area covering 

about half the cardinal area is minutely striated at 

right angles to the length. Hinge broadly arched on 

its lower margin, truncated above by the straight 

lower margin of the cardinal area; centrally the hinge 

is narrow and bears closely spaced, small transverse 

teeth; the hinge broadens toward the front and toward 

the rear, the broadened areas bearing numerous successively longer teeth which, away from the center, become 

more oblique inward and downward, the longer ones 

becoming angulated in trend. Inner margin smooth; 

on the interior of the left valve a groove that closely 

parallels the inner margin marks the contact of the 

margin of the slightly overlapped right valve. Other 

internal features not uncovered.

This species is closely allied, possibly ancestral to, 

Breviarca umbonata (Conrad) from the Snow Hill marl 

member of the Black Creek formation of North Carolina. (See Stephenson, 1923, p. 114; 1941, p. 86.) 

Compared with Conrad's species, B. subinflata is not 

so strongly inflated, is higher with respect to its length, 

and is more definitely subquadrate, as opposed to subtrigonal, in outline. These differences, though small, 

together with the lower stratigraphic position of the 

Georgia species, seem to justify the recognition of the 

latter as specifically distinct.

Types.—Holotype, from Ochillee Creek below bridge at old 

Ochillee, Chattahoochee County, Ga., USGS 15501, USNM 

125067; 1 figured paratype, same source, USNM 125068; 2 unfigured paratypes, same source, USNM 125069.

Distribution and range.—Known only from the lower part of 

the Eutaw formation at the type locality.

Breviarca symmetros Stephenson, n. sp. 

Plate 40, figures 1, 2

Shell small, moderately inflated, nearly symmetrical 

in form and in ovate outline, subequilateral, equivalve. 

Beaks small, subcentral, incurved, direct, slightly 

separated at the tips. Umbonal ridge practically 

wanting but the margin bulges slightly in the posteroventral direction. Dorsal margin broadly arched, 

anterior margin regularly rounded, ventral margin 

broadly rounded, posterior margin with narrowest 

curve below, broadening a little above. Surface with 

low, slightly irregular concentric riblets and fine weak 

radial lining.

Dimensions of the holotype, a left valve: Length 10.5 

mm, height 9.2 mm, convexity 3 mm. One of the paratypes, a left valve is 12 mm long.

Ligamental area amphidetic, elongate-triangular, 

scored with transverse, fine, closely spaced grooves; 

the apex of the area is central below the beak. Hinge 

plate long, narrow centrally, broadening at each end, 

arched on its inner margin, set with numerous teeth; 

the teeth are small and transverse to the hinge line 

centrally, becoming successively longer and more 

oblique on the broadened areas in each direction away 

from the center, attaining horizontality at the ends. 

Adductor scars large, subequal, subovate, their inner 

margins bounded by narrow, thin, weak radial carinae. 

Inner surface smooth, pallial line simple and well away 

from the inner margin, which is smooth.

Compared with Breviarca subinflata this species is 

less elongated, less inflated, and lacks an umbonal 

ridge, in which respect it resembles B. perovalis Conrad, 

B. subovalis Conrad, and B. congesta Conrad; it is 

smaller and less elongated than the first two named 

species, and is a little longer than B. congesta; it has a 

proportionately shorter and smaller ligamental area 

than either of the three species.

Types.—Holotype, from the upper part of the Eutaw formation in a cut of the new Hurtsboro Marvyn road 5.9 miles south 

of the Lee County line, in Russell County, Ala., USGS 25567, 

USNM 125070; 2 unfigured paratypes from the same locality, 

USNM 125071.

Range.—Known only from the type locality.

Breviarca? sp. 

Plate 40, figure 3

One small incomplete left valve of a bivalve mollusk 

(USGS 15501), probably a Breviarca, from Ochillee 

Creek below bridge at old Ochillee, Chattahoochee 

County, Ga., is similar in form and surface features to 

B. subinflata but is longer in proportion to the height. 

The umbonal ridge is subangular, sinuous, slightly
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 237

overhanging near the beak, becoming rounded on the 

crest toward the terminus. Posterodorsal slope narrow 

and slightly excavated. Beaks strongly incurved, 

nearly direct, situated about two-fifths of the length 

from the anterior end. Surface covered with low, 

weak, concentric ribs asymmetric in cross section, the 

lower slope of each rib gently inclined toward the venter, 

the upper slope steep and weakly crenulated by obscure 

fine radial lining. Dimensions: Length 10.5 mm, height 

6.3 mm, convexity about 2.5 mm. USNM 125072.

Genus TRIGONARCA Conrad, 1862 

Trigonarca inflata Stephenson, n. sp.

Plate 40, figures 4-8

Shell of medium size, thick-shelled, strongly convex, 

sub trigonal in outline. Beaks moderately prominent, 

incurved, opisthogyrate, widely separated, situated a 

little anterior to the midleiigth. Umbonal ridge 

rounded on crest, slightly curved, concave rearward in 

trend. The main surface rounds over regularly toward 

the anterior and ventral margins; posterodorsal slope 

steep, broadly excavated adjacent to margin. Growth 

lines sharp, resting stages marked by numerous concentric undulations. Obscure radiating lines detectable 

on parts of surface especially on anterior slope. Dorsal 

margin arched, anterior margin regularly rounded, 

ventral margin broadly rounded to nearly straight 

centrally, posterior margin sharply rounded below, 

truncated and inclined strongly forward above.

None of the adult shells is completely preserved; the 

holotype, a left valve, is broken away in a narrow strip 

around the anterior and ventral margins back to the 

pallial line. The approximate dimension of the holotype are: Length 60 mm, height 50 mm, convexity 

20 mm. None of the available shells exceeds these 

dimensions.

The ligamental area forms an obtuse-angled subtriangle with longest side at base, shortest side at rear 

and the third side broadly arched along the anterodorsal 

margin; six ligamental grooves, chevron-shaped, with 

short ends of grooves at rear. Hinge taxodont, hinge 

plate arched on lower margin, truncated on upper 

margin by the lower straight edge of the ligamental 

area. Teeth in two series separated by a short edentate area opposite the beak; starting at the rear 

end of the anterior series, the teeth are small, numerous, 

closely spaced transverse to hinge line, but in the forward direction they gradually become longer and 

oblique in trend; on the broad anterior part of the hinge 

plate of adults the otherwise long, oblique, angulated 

teeth become broken into small round-topped protuberances of irregular size and distribution. The 

posterior series of teeth is shorter than the anterior 

series and from front to rear includes several short

slightly oblique teeth, passing into longer angulated 

teeth and finally into successively shorter and more 

oblique teeth at the end of the series; all the teeth are 

striated on the sides at right angles to the hinge plate in 

the direction of movement. In a young shell (pi. 40, 

fig. 5) the long teeth are entire, and not broken into 

irregular pro tuber ences. Anterior adductor scar large, 

subovate, with a weak, narrow radial ridge along its 

posterior side; posterior scar smaller, elongated, seated 

on the outer end of a pronounced radial buttress. 

Pallial line simple. Inner surface scored with coarse 

radial grooves in a wide band bordering the inner side 

of the pallial line.

In form this species is similar to Trigonarca m,aconensis 

Conrad but the adult shells are much smaller, apparently more inflated, somewhat smoother, and the ligamental grooves are narrower and more numerous, 

T. inflata probably is ancestral to T. maconensis.

Types.—Holotype, a left valve from upper part of Eutaw formation in cut of Hurtsboro-Marvyn road, 5.9 miles south of 

Lee County line, in Russell County, Ala., USGS 25567, USNM 

125073; 1 figured paratype, a small right valve, same source, 

USNM 125074; 7 more or less incomplete, unfigured para types, 

6 right valves and 1 left valve, and several fragments, same 

source, USNM 125075.

Occurrence.—Known only from the type locality as indicated 

above.

Range.—Upper part of Eutaw formation.

Superfamily PTERIACEA

Family PTERIIDAE 

Genus PSEUDOPTERA Meek, 1873

Meek (1873, p. 489; 1876, p. 29) proposed the name 

Pseudoptera as a subgenus of Pteria Scopoli. He designated as genotype Avicula anomala Sowerby, as figured 

by d'Orbigny (1843-47, p. 478, pi. 392). It would appear that the species illustrated by d'Orbigny must be 

accepted as the genotype of Pseudoptera, although it is 

the true A. anomala Sowerby, the type of which is not 

illustrated by Woods (1905, p. 64, pi. 9, fig. 2a), 

D'Orbigny's figured specimen is from the lower Turonian at Le Mans, Department of Sarthe, France; 

Sowerby's specimen, the true A. anomala is from the 

Upper Greensand (Albian) at Blackdowii, Devonshire, 

England. The two species probably belong to the 

same genus.

The specimens referred to Pseudoptera in this paper 

are similar in form to the one from Le Mans figured by 

d'Orbigny; the right valves are, however, more flatly 

compressed. . There is also a marked difference in the 

surface ornamentation, the specimens from the Eutaw 

formation having radial lining only on the anteroventral 

slope of left valves. The features of the ligamental area 

are well shown on two of the specimens from the Eutaw 

formation, whereas this area was not seen by either 

Sowerby or d'Orbigny.
238 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Pseudoptera securiformis Stephenson, n. sp. 

Plate 40, figures 9, 10; plate 41, figures 12-14

Shell large, subtrigonal in outline, inequivalve, 

strongly inequilateral, bent conspicuously to the left 

in the adult stage, probably slightly gaping at the rear. 

In some specimens the curvature to the left is not apparent because of subsequent mechanical flattening. 

The left valve is moderately convex, the maximum inflation is along the umbonal ridge, which extends in a 

nearly straight or slightly sinuous course from the umbo 

to the lower posterior extremity, forming an angle to 

the hinge line ranging in different individuals from 50° 

to 65°. A narrow, sharply upraised, somewhat irregular 

ridge traverses the crest of the umbonal ridge from the 

beak to the lower posterior extremity.

The surface back of the umbonal ridge forms a broad 

very gently convex, slightly undulating slope to the 

dorsal margin and to the posterior margin; near the 

hinge line the surface flattens out a little to form an 

ill-defined posterior wing or rostrum. The anteroventral 

slope is steep and short and toward the front flares out 

to form a relatively narrow anterior ear that projects 

about 10 millimeters in advance of the beak in adults. 

'The right valve is nearly flat or only gently convex, 

conforming, however, to the curvature of the shell to 

the left; it is smaller than the left valve, which overlaps 

it conspicuously along the anteroventral margin.

Dorsal margin of shell straight, about three-fourths 

the total length of the shell; anterior end subpointed; 

anteroventral margin descending, long, broadly convex; 

posterior margin narrowly rounded below; posterodorsal margin broadly convex, inclined forward, curving 

upward slightly to meet the hinge line. The surface of 

the shell, especially of the left valve, bears coarse, 

.sharp growth lines. The surface back of the umbonal 

ridge of the holotype and of some other specimens bears 

two broad, low diverging radiating folds, but these 

folds appear to be wanting on many specimens. A series 

of narrow, obscure to moderately pronounced, irregularly serrated radiating ribs are present on the anteroventral slope of most left valves the shell substance 

of which is preserved, but this is a variable feature.

Approximate dimensions of the holotype, a left valve: 

Length 100 mm, height 70 mm, maximum convexity 

about 25 mm. Some shells attain a length of 120 mm.

The features of the ligamental area are preserved on 

two of the paratypes. The area is wide and bears 5 or 6 

ligamental pits of differing width and spacing; the pits 

are wider than the intervening spaces. The hinge 

appears to lack dentition but near the anterior end of 

the cardinal area a little back of the beak is a narrow, 

nonprominent ridge extending obliquely inward to the 

Inner edge of the area; in front of and parallel to this

ridge is a wide and deep channel that ends beakward in 

a small pit. No evidence of the position of the main 

adductor scar can be detected on the available internal 

molds but there is the clear impression of a small muscle 

scar (retractor?) 5 or 6 mm inward from the inner edge 

of the cardinal area and 25 or 30 mm inward from the 

beak.

Types.—Georgia: Holotype, from Ochillee Creek at old 

Ochillee, Ga., USGS 15501, USNM 125076; 1 unfigured paratype, same source, USGS 5374, USNM 125077; 1 unfigured paratype, same source, USGS 5378, USNM 125078; 1 unfigured paratype, same source, USGS 15501, USNM 125079; 1 

figured paratype, same source, USGS 25570, USNM 125082; 1 

figured paratype, USGS 5377, USNM 125080. Alabama: 2 

figured paratypes, USGS 5384, USNM 125081; two unfigured 

paratypes, USGS 848, USNM 125083.

Distribution.—Chattahoochee County, Ga.: Chattahoochee 

River, Broken Arrow Bend, left bank, about 10 miles below 

Columbus, USGS 847; about 0.5 mile below Broken Arrow Bend, 

USGS 5385; Upatoi Creek, left bank, 0.25 mile below the old 

Columbus-Cusseta road bridge, USGS 5373 + 5377 »; Ochillee 

Creek near old Ochillee, USGS 5374 + 5378 + 15501 + 25570; 

Russell County, Ala.: Chattahoochee River, Broken Arrow 

Bend, right bank, about 10 miles below Columbus, Ga., USGS 

5384 + 6409; just below Burdock Landing, USGS 848; Slick 

Bluff, USGS 845; old Marvyn road, 2.7 miles (airline) north by 

west of Uchee, USGS 17211; Hurtsboro-Marvyn highway 5.75 

miles south of Lee County line, USGS 25575. Perry County, 

Ala.: Road cut in northward-facing slope 1.7 miles northeast of 

old Hamburg, USGS 25467.

Range.—The species, as known, ranges through the Eutaw 

formation of east-central Alabama and adjacent parts of 

Georgia; one specimen has been found in the basal bed of the 

Mooreville chalk. Within the Eutaw formation the species 

ranges from the base nearly to the top.

Superfamily OSTRACEA

Family OSTREIDAE

Genus OSTREA Linne, 1758

Subgenus LOPHA Bolten, 1798

Ostrea (Lopha) ucheensis Stephenson, n. sp.

Plate 43, figures 1-5

Shell of medium size, subtrigonal to subcircular in 

outline, with a tendency for the steeply descending 

posterodorsal margin to be nearly straight. Right and 

left valves low-convex to nearly flat. Both valves 

ornamented with radiating, coarse, round-crested ribs 

or folds numbering 5 to 10 on different individuals, the 

folds of one valve corresponding to the intercostal 

spaces of the other valve, the two valves intermeshing 

around the margins. A smooth flattish area extending 

15 to 30 millimeters out from the beak on each valve 

of most individuals is unaffected by the folds. Growth 

lines fine on the umbonal area, becoming coarser to

i Numbers connected by the plus sign (+) pertain to the same locality.
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 239

roughly imbricating toward the outer margins. Beaks 

iionprominent, more or less pointed with a tendency 

to an angulatioii of 90° to 115°.

Dimensions of the holotype, a left valve: Length 

65 mm, height 66 mm, convexity about 10 mm. The 

largest shell in the collection, a right valve, is 67 mm 

long and 75 mm high.

Ligamental pit relatively small, short, triangular, 

straight or slightly curved, opening widely to the 

interior. Inner margin smooth except for the coarse 

flutings caused by the intermeshing of the external 

folds. Adductor scar elongate, more than twice as 

long as wide, curved, bean-shaped, with the convexity 

toward the outer margin.

Types.—Holotype, from hill 31/! miles north-northwest of 

Uchee, Russell County, Ala., beds of Eutaw formation exposed 

in gullies in field southwest of road, USGS 17583, USNM 

125031; 7 unfigured paratypes, same source, USNM 125032; 3 

figured paratypes, USGS 18317, USNM 125033; 5 unfigured 

paratypes from the preceding locality, USNM 125034; 6 unfigured paratypes, USGS 17585, USNM 125035.

Distribution.—Russell County, Ala.: This species is found 3.2 

to 3.4 miles (airline) northwest of Uchee, USGS 17583 + 18317; 

2.6 to 2.9 miles north by west (airline) of Uchee, USGS 17585 + 

17766 + 18309; 5 miles northwest (airline) of Seale, USGS 

18308; Chattahoochee River at Burdock Landing, USGS 848, 

and Slick Bluff, USGS 845 + 5387. Dallas County, Ala.: One 

and one-half miles southeast of Summerfield, USGS 19546.

Range.—In Russell County, Ala., the known occurrences of 

this species are all in the upper part of the Eutaw formation, 

probably within the upper 50 feet. The one recorded occurrence 

in Dallas County, Ala., is in the Eutaw formation, but its exact 

stratigraphic position within that unit has not been determined.

Ostrea cretacea Morton 

Plate 40, figures 11, 12; plate 42, figures 1-17

1834. Ostrea cretacea Morton, Synopsis of the organic remains 

of the Cretaceous group of the United States, p. 52, 

pi. 19, fig. 3. (See synonymy in N. C. Geol. and Econ. 

Survey, v. 5, pt. 1, p. 134, 1923.)

The probable validity of the name Ostrea cretacea 

Morton for the abundant small oyster shells in the 

Eutaw formation (Tombigbee sand member) at Erie 

Bluff, Hale County, Ala., is discussed by Stephenson 

(1923, p. 135). Further consideration of the subject 

has afforded no basis for changing the opinion expressed 

at that time. I believe that the types in the Academy 

of Natural Sciences, Philadelphia, Pa., came from the 

Eutaw formation at Erie Bluff, Warrior River, Hale 

County, Ala., and that the label attributing them to 

Charleston, S. C., is in error; these specimens agree 

closely with shells from Erie Bluff.

A comparison of Morton's original figure of Ostrea 

cretacea with the original figure of 0. alabamiensis 

Lea (1833, p. 91, pi. 3, fig. 17) fails to justify Ball's 

(1898, p. 679) placing of Morton's species in the synonomy of Lea's species; the two species differ markedly

in form and outline, and 0. cretacea is smooth on the 

inner margin, with the exception of a few obscure 

crenulations near the hinge of some shells.

Ostrea cretacea Morton is a small simple nearly 

straight, or only slightly curved, oyster, subovate to 

subtrigonal in outline, both valves low-convex. Concentric markings pronounced but variable in strength 

and spacing on different individuals. Radial markings 

practically absent, but a few obscure radial lines may 

be detected on some shells, including the holotype. 

The shells exhibit marked individual variation in outline and convexity; the dorsal margin may be broad or 

narrow and pointed. Radial color markings of brownish 

tint are preserved on a rare specimen (pi. 40, fig. 12).

The recorded dimensions of the holotype are: Length 

24 mm, height 34 mm, convexity 6 mm. Among the 

specimens referred to the species in the present paper 

the largest measured shell, a left valve (pi. 42, fig. 14), 

is 43 mm long, 57 mm high, and has a convexity of 

about 15 mm.

In Alabama Ostrea cretacea Morton is restricted in 

vertical range to the Eutaw formation. At Erie Bluff 

on Warrior River, Hale County, the type locality, the 

zone containing this species is about 21 feet thick; the 

zone is uncomformably overlain by the Mooreville 

chalk of the Selma group. The same zone bearing 

great numbers of the shells of 0. cretacea is well exposed 

at Choctaw Bluff, Greene County, about 6 miles (airline) upstream from Erie Bluff, and at Wolfs Bluff, 

Hale County, less than a mile downstream from Erie 

Bluff. In a road cut 1.7 miles northeast of old Hamburg, 

Perry County, Ala., the zone yielding the species is 

only about 10 feet thick and occupies the same stratigraphic position below the Mooreville chalk that it 

does at Erie Bluff.

In east-central Alabama in Macon and Russell 

Counties the zone of Ostrea cretacea is much thicker 

than it is in the central and western parts of the state, 

attaining a measured thickness of 130 feet. In these 

counties the shells of the species are present in vast 

numbers in certain layers, especially in the upper part 

of the zone. In this area the shells average a little 

larger than at the type locality at Erie Bluff. However, 

the size ranges from that of the smaller more typical 

shells to about one and four-fifths that of the holotype, 

and there seems no reason to question the reference of 

all the shells to 0. cretacea Morton. Presumably the 

average greater size of the shells in some assemblages 

reflects the more favorable environmental conditions 

in which the organisms lived.

Types.—Holotype and three paratypes in the collection of the 

Academy of Natural Sciences of Philadelphia; these are labeled 

"Charleston, S. C.," but for reasons previously stated this label 

is believed to be in error, the true type locality being, Erie Bluff,

389135—5€
240 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Warrior River, Ala. On the assumption that Erie Bluff is the 

type locality, the four shells illustrated by Stephenson (1923, 

pi. 28, figs. 11-13, USNM 31541-31544) are topotypes.

Two plesiotypes (essentially topotypes), Choctaw Bluff, 

Warrior River, Greene County, Ala., USGS 6425, USNM 

125025; 2 figured topotypes, Erie Bluff, Warrior River, Hale 

County, Ala., USGS 6428, USNM 125026; 3 pleisotypes, 4.1 

miles north of Creek Stand, Macon Co., Ala., USGS 17007, 

USNM 125027; 7 plesiotypes about 3.1 miles north of Creek 

Stand, Macon County, Ala., USGS 17006, USNM 125028;

1 plesiotype, 5 miles northwest of Seale, Russell County, Ala., 

USGS 18308, USNM 125029; 2 plesiotypes, left valves, half mile 

below Broken Arrow Bend, about 10 miles below Columbus, in 

Chattahoochee County, Ga., USGS 5385, USNM 125030.

Distribution.—The shells of Ostrea cretacea Morton may be 

seen in outcrops of the Tombigbee sand member of the Eutaw 

formation at many places between Greene County, Ala., and 

Chattahoochee River, and at a few places in Chattahoochee 

County, Ga. Only a few localities at which the shells have been 

•collected will be recorded here.

Alabama: Greene County, Choctaw Bluff, Warrior River, 

USGS 6425; Hale County, Warrior River at Erie Bluff, USGS 

6428+6932 and at Wolfs Bluff, USGS 6429; Perry County, 1.7 

miles northeast of old Hamburg, USGS 6441; Macon County,

2 miles north of Warrior Stand, USGS 17574, 2.3 miles northwest of Warrior Stand, USGS 17550, 3.1 miles north of Creek 

Stand, USGS 17006, and 4 miles (airline) north of Creek Stand, 

USGS 17007; Russell County, 2.5 miles north-northwest of 

Uchee, USGS 17766 + 17776, Hurtsboro-Marvyn road 5.85 miles 

south of Lee County line, USGS 25575, 3.4 miles northwest of 

Uchee, USGS 17775, 5 miles northwest of Seale, USGS 18308, 

Chattahoochee River, right bank, at Broken Arrow Bend, 

USGS 5384, and just below Burdock Landing, USGS 5386.

Georgia: Chattahoochee River, left bank, one-half mile below 

Broken Arrow Bend, USGS 5385, Upatoi Creek 7 miles southeast 

of Columbus, USGS 5373 + 5377+17612, Ochillee, USGS 

5374+5378+15501.

South Carolina: Well of Charleston Consolidated Railway and 

Lighting Co., Charleston, at several depths between 1,725 and 

2,007 feet.

North Carolina: Well of Clarendon Waterworks Co., Wilmington, at depths between 720 and 1,105 feet; well at Fort 

Caswell at depth of 1,365 to 1,380 feet. (See Stephenson, 1923, 

p. 136.)

Range.—Shells of this species occur in vast numbers in certain 

beds of the Eutaw formation in Alabama and in adjacent parts 

of Georgia. Some shells that seem indistinguishable from the 

«pecies have been recorded from overlying formations in 

Georgia, North Carolina, and South Carolina as high as the upper part of the Exogyra ponderosa zone.

Genus GRYPHAEA Lamarck, 1801, sensu lato 

Gryphaea wratheri Stephenson

Plate 41, figures 3-8

1936. Gryphaea wratheri Stephenson, U. S. Geol. Survey Prof. 

Paper 186-A, p. 2, pi. 1, figs. 1-4.

The original description of Gryphaea wratheri Stephenson and a record of the distribution of the species 

us known at that time, are given in the paper cited in 

the synonymy. (See also Stephenson, 1937, p. 133- 

146.) The species is closely related to Q. aucdla 

JRoemer but averages larger, thicker shelled, broader,

less convex and is less strongly incurved at the beak. 

A consistent difference between the two species that 

was not mentioned in the original description pertains 

to a calluslike ridge or fold marking the contact between 

the two valves on the inner surface of the shell; in a 

typical example of Q. wratheri this feature appears as a 

conspicuous round-crested concentric ridge extending 

around the inner surface at the line of contact of the 

two valves, terminating at its two ends below the beak 

at the inner angles of the ligamental pit. The strength 

of this ridge varies markedly on different individuals. 

In Q. aucetta either no ridge is present at this line of 

contact, or if present is only weakly developed at the 

ends of the line nearest the ligamental pit. As in most 

species in the oyster family the shells of G. wratheri 

have marked individual variation in shell characters.

The left valve shown in plate 41, figure 5, measures: 

Length 32 mm, height about 33 mm, convexity about 

12 mm. The average size of the Alabama shells is about 

the same as that of the more typical ones from eastcentral Texas. However, a few may attain a size and 

thickness considerably greater than the average. One 

such shell (pi. 41, fig. 3) from House Bluff, Alabama 

River, Autauga County, measures: Length 56 mm, 

height 58 mm.

Types.—Holotype, USNM 75506; 2 figured paratypes, 

USNM 75507, 75507a; 36 unfigured paratypes, USNM 75508; 

all from a cut on Gaston Avenue just northeast of the intersection 

of West Shore Drive, 0.7 mile west of the dam of White Rock 

Reservoir, Dallas, Tex.; all are from USGS coll. 14075. Plesiotype from 0.5 mile north by east of Liberty Hill Church, Macon 

County, Ala., USGS 19060, USNM 125022; 2 plesiotypes from 

0.75 mile north by east of Liberty Hill Church, Macon County, 

Ala., USGS 17576, USNM 125023. Plesiotype from House 

Bluff, Alabama River, Autauga County, Ala., USGS 6442-B, 

USNM 125024.

Distribution in eastern Alabama.—Macon County, upper part 

of Eutaw formation: 4.25 miles N. of Chesson, USGS 17570; 

2/l 2 miles northeast of Hardaway, USGS 17761; 2 miles north of 

Edwards, USGS 17572; 7 miles northeast of Hardaway, % mile(?) 

north-northeast of Liberty Hill Church, USGS 19060 (1 plesiotype), 17763; 0.75 mile north by east of Liberty Hill Church, 

USGS 17576 (2 plesiotypes), 17764; about 7 miles northeast of 

Hardaway, 0.1 to 0.3 mile south of Mount Andrew Church, 

USGS 17771; Fort Davis road 6 miles south of Tuskegee, USGS 

6445; 6.1 miles north by east of Fort Davis, USGS 17569; 2.5 

miles north of Cotton Valley crossroad, USGS 17608; 2.35 miles 

north of Cotton Valley crossroad, USGS 17607; 2.25 miles northnorthwest of Warrior Stand, USGS 18306; 2 miles north of Warrior Stand, USGS 17574; 4.1 miles north by west of Creek Stand, 

USGS 18312. Macon County, base of Bluff town formation: 

0.75 miles north by east of Chesson, USGS 17568; 2.5 miles 

northeast of Hardaway, USGS 17573.

Russell County, upper part of Eutaw formation: Uchee Creek 

200 feet upstream from crossing of U. S. Highway 241 [431], 

USGS 19079. Russell County, lower part of Mooreville chalk 

(sandy facies): 0.55 miles north of Hurtsboro, USGS 18320; 2.5 

miles east by north of Hurtsboro, USGS 17604; State Highway 

26, 3.4 miles east of Hurtsboro, USGS 18318+25583.
FOSSILS OF THE BUT AW FORMATION, ALABAMA-GEORGIA 241

Stratigraphic and geologic range.—The original description of 

the species (Stephenson, 1936, p. 3, 4) records it from the upper 

part of the Tombigbee sand member of the Eutaw formation 

and from the basal bed of the Mooreville chalk (Selma group) 

at 15 localities in Alabama between the vicinity of Eutaw, 

Greene County, and Montgomery, Montgomery County. Part 

of the shells from the basal Mooreville were mechanically reworked from the underlying Eutaw formation, but some may be 

indigenous to the basal Mooreville. The more recent field work 

of W. H. Monroe and others in eastern Alabama has resulted in 

the discovery of G. wratheri in Macon and Russell Counties in 

the upper part of the Eutaw formation in that area, where also 

a few indigenous examples of the species have been found in the 

lower part of the Mooreville chalk (sandy facies).

Subsequent to the publication of the original description, the 

species has been recorded from the upper part of the Tombigbee 

sand member of the Eutaw formation in Mississippi (Stephenson 

and Monroe, 1940, p. 69). The species has been obtained from 

a core sample (USGS 25369), depth 4,-324-4,326 feet, in a well 

of the Shell Oil Co. in the Chaperall field, Sistrunk-Chap man 

Bl, sec. 13, T. 10 N., R. 7 W., Wayne County, Miss.; this material was submitted by E. H. Rainwater November 22, 1954, and 

was identified by Norman F. Sohl.

In east central Texas Gryphaea wratheri is present within the 

upper half of the Austin chalk in a zone having a maximum observed thickness of 35 feet; this zone has been traced through 

the chalk from the type locality of the species in Dallas, Dallas 

County, Tex., southward and southwestward to Guadalupe 

County, Tex.; the species has also been recorded in a marine 

sand that probably represents the westward continuation of the 

Blossom sand (late Austin age) at two localities, one about 3 

miles north by west of Dodd City, and the other about 5 miles 

north of Windom (north of Lone Elm Church), Fannin County, 

Tex.

In recent years the species has been identified in west Texas 

in Jeff Davis, Reeves, and Presidio Counties. These examples 

possess the essential features of the species but are notable for 

their larger average size and their thick shells, indicating vigorous 

growth in a favorable habitat. Some shells attain lengths as 

great as 50 mm, heights as great as 64 mm, and a maximum 

thickness (diameter) of 15 mm.

Genus EXOGYRA Say, 1920

Exogyra upatoiensis Stephenson

Plate 43, figures 6-10

1914. Exogyra upatoiensis Stephenson, U. S. Geol. Survey Prof.

Paper 81, p. 46, pi. 13, figs. 5-7; pi. 14, figs. 1-3. 

1923. Exogyra upatoiensis Stephenson. Stephenson, N. C.

Geol. and Econ. Survey, v. 5, p. 164, pi. 45, figs. 1-5.

Two of the three cotypes of this species came from 

the basal beds of the Eutaw formation at Broken Arrow 

Bend on Chattahoochee River, about 10 miles below 

Columbus and the third from a locality on Upatoi 

Creek 6 miles east-northeast of Broken Arrow Bend, 

Chattahoochee County, Ga. (7 miles southeast of 

Columbus). The species is described and illustrated 

in the two papers cited in the synonymy. The left 

valves of two of the cotypes are well formed and are 

ornamented all over with fine, closely spaced, irregular 

radial costae. The left valve of the larger of the three

cotypes shows fine radial costae in the umbonal region 

around a very large scar of attachment, but elsewhere 

is partly smooth and partly ornamented with short, 

irregular costae; the costae on the umbonal ridge are 

somewhat coarser than on other parts of the surface.

West of Chattahoochee River in Russell and Macon 

Counties, and on to the west in Alabama, the species is 

represented in collections from many localities by shells, 

mainly in the upper part of the Eutaw formation 

(Tombigbee sand member), that exhibit a wide individual range in the form and ornamentation of their 

left valves. Among these shells a few possess the features of the originally described shells from the type 

area, but most of them are irregular in form as a result 

of crowding or other unfavorable environmental conditions. Many of these nontypical shells have a minor 

development of fine, closely crowded typical costae in 

the umbonal region, away from which the surface bears 

relatively coarse, irregularly distributed costae; on the 

crests of the costae are scattered spinelike projections 

formed by the sharp upfolding of concentric lamellae. 

Although many of these shells are nontypical in appearance there is a reasonable certainty that they all belong 

to Exogyra upatoiensis Stephenson, and that they are 

individual variants within the species.

Types.—Cotypes from basal beds of Eutaw formation, Chattahoochee River, Broken Arrow Bend, about 10 miles below Columbus, right bank (Alabama), USGS 5384, USNM 31219, 31221, 

and Upatoi Creek 7 miles southeast of Columbus, Chattahoochee 

County, Ga., USGS 5377, USNM 31220. Plesiotypes from 

upper part of Eutaw formation (Tombigbee sand member) 2.25 

miles north-northwest of Warrior Stand, USGS 18306, USNM 

125018; and 0.75 mile north by east of Liberty Hill Church, 

USGS 17576, USNM 125019, Macon County, Ala.; Catoma 

Creek 5 or 6 miles southwest of Montgomery, Montgomery 

County, Ala., USGS 17010, USNM 125020. Plesiotype from 

base of Mooreville chalk, Choctaw Bluff, Warrior River, 4 

miles south by east of Eutaw, Greene County, Ala., USGS 

25466, USNM 125021.

Distribution.—Greene County, Ala. (base of Mooreville chalk): 

Choctaw Bluff, Warrior River, USGS 25466 (1 plesiotype). 

Autauga County, Ala. (upper part of Eutaw formation): House 

Bluff, Alabama River, USGS 17011. Montgomery County, Ala. 

(upper part of Eutaw formation): Catoma Creek, 5 or 6 miles 

southwest of Montgomery, USGS 17010 (includes 1 plesiotype). 

Macon County, Ala. (Eutaw formation): 4.25 miles north of 

Chesson, USGS 17570; 2.5 miles northeast of Hardaway, USGS 

17761; 2 miles north of Edwards, USGS 17572; 0.5 mile northnortheast of Liberty Hill Church, USGS 17763; 0.75(?) mile 

north by east of Liberty Hill Church, USGS 19060; 0.75 mile 

north by east of Liberty Hill Church, USGS 17576 (includes 1 

plesiotype); 0.1 to 0.3 mile south of Mount Andrew Church, 

USGS 17771; 2.5 miles north of Cotton Valley crossroad, USGS 

17608; 2.25 miles north-northwest of Warrior Stand, USGS 

18306 (includes 1 plesiotype); 2 miles north of Warrior Stand, 

USGS 17574; 4.1 miles north by west of Creek Stand, USGS 

11646+17007+17212. Russell County, Ala. (Eutaw formation): 

3.8 miles north by west of Uchee, USGS 17585; 3.25 miles northnorthwest of Uchee, USGS 17583+17584; Chattahoochee River,
242 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Broken Arrow Bend, right bank, about 10 miles below Columbus, 

USGS 5384; near Fort MitcheU Landing, USGS 575. Chatta- 

"hoochee County, Ga. (basal beds of Eutaw formation): Chatta- 

"hoochee River, Broken Arrow Bend, left bank, about 10 miles 

below Columbus, USGS 847 (includes 2 cotypes), 25573; Upatoi 

Creek, 7 miles southeast of Columbus, USGS 5373+5377 

(includes 1 cotype).

Range.—The species, as at present satisfactorily identified, is 

restricted in its stratigraphic range to the Eutaw formation in 

central and east-central Alabama and in Chattahoochee County, 

Ga., and is recorded from a well at Charleston, S. C., at a depth

•of 1,974 to 2,007 feet. Examples found in the basal bed of the 

Mooreville chalk in Alabama are believed to have been mechanically reworked from the underlying Tombigbee sand member of 

the Eutaw formation.

Superfamily ANOMIACEA

Family ANOMIIDAE

Genus ANOMIA Linne, 1758

Anomia preolmstedi Stephenson, n. sp.

Plate 41, figure 9-11

Left valve of medium,sized shell thin, subcircular in 

outline, flattish to strongly convex in different individuals, approximately equilateral. The beak is not 

preserved on most of the available shells but, as seen on 

two young left valves, it is small, nonprominent, and is 

situated about 1 millimeter away from the margin. 

The surface of well-preserved shells bears very fine, 

irregular, more or less obscure, closely spaced riblets 

and fine, closely spaced, overlapping concentric 

lamellae. The whole outer surface presents a characteristic soft silvery sheen. Hinge edentulus. Inner 

surfaces of available left valves not well enough preserved to show the muscle scars. The inner surface of 

the figured paratype is lined with a thin layer of matrix 

filling, the outer surface of which bears the imprint of 

the right valve. This imprint is smooth and undulating; 

a little below the hinge margin is the outline of the oval

•opening (foramen) through which passed the byssus that 

provided the mechanism for the attachment of the 

animal to a foreign object, as for example, to the surface 

of an abandoned moluscan shell. No right valves are 

present in the material studied and the imprint just 

described is the only observed evidence of its presence. 

Although the genus Anomia is represented in our collections from the Cretaceous sediments of the Atlantic 

and Gulf Coastal Plain by several species and by many 

individuals, right valves are rarely seen. This is 

because they are thin and frail and are easily destroyed; 

in an exceptional example the right valve is protected 

by the overlying left valve which has retained its 

natural position on the object of attachment.

Dimensions of the holotype: Length 33 mm, height 

31 mm. convexity 9 mm. A large and exceptionally

convex left valve measures: Length 35 mm, height 

36 mm, convexity about 15 mm.

Shells of this species from the Eutaw and Blufftown 

formations in the Chattahoochee area south and southeast of Columbus, Ga., have heretofore been referred to 

Anomia olmstedi Stephenson (Stephenson, 1923, p. 219), 

but these shells present certain consistent differences 

from A. olmstedi, and occupy a lower stratigraphic position than that species. In A. preolmstedi Stephenson 

the riblets covering the outer surface of the left valve 

are finer and weaker than the similar riblets in A. 

olmstedi and the concentric growth lamellae, although 

similar in appearance, are finer and more closely spaced 

and are not conspicuously upraised along their free 

margins.

Types.—Holotype, from Chattahoochee River, Broken Arrow 

Bend, right side, about 10 miles below Columbus, in Russell 

County, Ala., USGS 6409, USNM 125014; 1 figured paratype 

from same source, USNM 125015; 8 unfigured paratypes (from 

same source), 2 mentioned, USNM 125016; 2 unfigured paratypes, the large one measured, from Ochillee, Chattahoochee 

County, Ga., USGS 5378, USNM 125017.

Distribution.—Alabama, Russell County: Eutaw formation, 

Broken Arrow Bend, Chattahoochee River, right side, about 10 

miles below Columbus, Ga., USGS 5384 + 6409 (holotype and 

9 paratypes); just below Burdock Landing, Chattahoochee River 

about 13.5 miles below Columbus, USGS 5386; northeastward 

facing slope of small branch of Uchee Creek, 2% miles north by 

west of Uchee, USGS 17759 + 17765 + 17769; gullies southwest 

of road 3}£ miles north-northwest of Uchee, USGS 17584. 

Blufftown formation, Big Bend, Chattahoochee River, 24.5 miles 

below Columbus, USGS 5388.

Georgia, Chattahoochee County: Eutaw formation, Ochillee 

Creek at old Ochillee, USGS 5378 (2 paratypes, 1 measured) ; 

Chattahoochee River, Broken Arrow Bend, left bank, about 10 

miles below Columbus, Ga., USGS 847. Blufftown formation, 

just below Banks Landing, Chattahoochee River, 27 miles below 

Columbus, in Stewart County, USGS 5390.

Range.—The species ranges through the Eutaw formation of 

the Chattahoochee area and upward into the lower part of the 

Blufftown formation (Mooreville age).

Order TELEODESMACEA 

Superfamily CARDIACEA

Family CARDHDAE

Genus CARDIUM Linne, 1758

Subgenus TRACHYCARDIUM Morch, 1853

Cardium (Trachycardium) ochilleanum Stephenson, n. sp.

Plate 41, figures 1, 2

Shell of medium thickness, subquadrangular in outline, length and height nearly equal, moderately convex, a little oblique toward the lower rear. Beaks of 

medium prominence, incurved, closely approximate, 

slightly prosogyrate, situated centrally. Umbonal 

ridge of medium prominence, obtusely subangular in 

cross section. Posterodorsal slope steep, broadly exca-
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 243

vated. Main surface rounding down broadly to the 

anterior and ventral margins. Dorsal margin short, 

slightly arched; anterior margin semicircular, rounding 

into the broadly rounded ventral margin; posterior 

terminus subangular below the midheight; posterior 

margin above the terminus truncated, inclined forward. 

The surface bears about 38 well-developed radiating 

ribs; these are flattish-topped with the exception of 

several ribs on the umbonal ridge, which are sharp 

crested. On about the anterior three-fifths of the surface the ribs bear regularly spaced nodes elongated 

transversely and, where largest, numbering about 8 

in a radial distance of 5 millimeters; toward the beak 

on each rib the nodes become regularly smaller and 

weaker and are scarcely observable near the tip of 

the beak. The nodes are in alinement from rib to 

rib and the rows of nodes appear to be in alinement 

with the fine growth lines. On the posterior twofifths of the surface the crests of the ribs are essentially 

smooth with the exception of obscure irregular nodes 

on the posterodorsal slope.

Dimensions of the holotype, a right valve: Length 

28 mm, height 29 mm, convexity about 12 mm. The 

figured paratype, a left valve, is 24 mm long and 24 

mm high.

The hinge is imperfectly preserved in the holotype 

and the figured paratype, but the features are observable in part. Hinge narrow; ligamental groove short, 

opisthodetic; the cardinal teeth of the right valve 

include a small anterior tooth and a relatively large 

posterior tooth (broken away), separated by a deep 

socket; in the left valve the anterior cardinal (also 

broken away) is large and the posterior one small, 

the two separated by a deep socket; the lateral teeth 

are small and well removed from the cardinals. 

Internal features not uncovered.

This species is closely related to Cardium (Tracfiycardium) carolinense Conrad (1875), in Kerr, W. C., 

app. A, p. 7; Stephenson, 1923, p. 286), from the Snow 

Hill marl member of the Black Creek formation, Snow 

Hill, N. C. It differs from that species in that the 

ribs are narrower, the interspaces are wider, and the 

pattern of the nodes, though similar, is much coarser.

Types.—Holotype, a right valve from Ochillee Creek, below 

bridge at site of old Ochillee, Chattahoochee County, Ga., 

USGS 15501, USNM 125010; 1 figured paratype, same source, 

USNM 125012; 2 unfigured juvenile paratypes, a right and a 

left valve, same source, USNM 125011; 1 unfigured paratype, 

same source, USGS 25569, USNM 125013.

Distribution and range.—The only available specimens are 

the types from the Ochillee Creek locality.

Superfamily VENERACEA

Family VENERIDAE

Genus LEGUMEN Conrad, 1858

Legumen aff. L. carolinense (Conrad)

Plate 44, figures 17-20

The internal and external molds of a species of 

Legumen Conrad are common in the Eutaw formation 

in the Chattahoochee River area (Georgia-Alabama). 

In outline and form, and in the character of the concentric growth markings on the outer surface of the 

shell this species appears to be essentially like L. carolinense (Conrad) from the Snow Hill marl member of 

the Black Creek formation of North Carolina (Conrad, 1875, p. 8, pi. 2, fig. 10; Stephenson, 1923, p. 321, 

pi. 81, figs. 5-8). The part of the Chattahoochee 

River section that corresponds in age to the Snow 

Hill marl member is the Cusseta sand which unconformably overlies the Blufftown formation. Legumen 

carolinense is recorded from a marine facies of the 

Cussetta sand exposed at Woolridge Landing, Chattahoochee River, near the northeastern corner of Barbour 

County, Ala.

In the Chattahoochee region the Eutaw formation 

forms the lower part of the zone of Exogyra ponderosa, 

whereas the Cusseta sand forms the upper part of 

that zone above the Blufftown formation. If the 

molds and prints of Legumen in the Eutaw are correctly 

referable to L. carolinense the indicated range of thespecies is through the zone of E. ponderosa.

Although the prints and molds of Legumen in the 

Eutaw formation are like L. carolinense in most of their 

features there are minor differences that appear to be 

consistent so far as the available material permits on& 

to judge. The pallial sinus, as obscurely preserved on 

several of the internal molds from the Eutaw, is narrower than it is in L. carolinense, and the anterior margin 

of the shell appears to be more narrowly rounded. If 

these differences should prove to be constant features 

they might justify a specific separation. However, 

granting the reality of these differences the conclusion 

may reasonably be drawn that the form of Legumen so 

abundantly present in the Eutaw formation is ancestral 

to L. carolinense in the Cusseta sand and in the Snow 

Hill marl member of the Black Creek formation. The 

hinge features, which are so perfectly preserved in the 

cotypes of L. carolinense from North Carolina, are not 

observable on the molds and prints from the Eutaw 

formation in the Chattahoochee River area. However,, 

imprints of the inner edges of the cardinal teeth on the-
244 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

dorsal margin of the internal molds agree in their 

arrangement with the cardinal teeth of L. carolinense, 

and the reference of the molds to the genus L. Conrad 

seems well established.

The internal mold shown in plate 44, figure 19, 

measures: Length 58 mm, height 34 mm, thickness 13 

mm; the mold shown in plate 44, figure 17, measures: 

Length 52 mm, height 32 mm, thickness 13.5 mm.

Figured specimens.—Broken Arrow Bend, Chattahoochee 

River, Chattahoochee County, Ga., USGS 6408, USNM 125006; 

Upatoi Creek, 7 miles southeast of Columbus, in Chattahoochee 

County, Ga., USGS 5377, USNM 125007; just below Burdock 

Landing, Chattahoochee River, Russell County, Ala., USGS 

848, USNM 125008; 1 unfigured specimen from the same source, 

USGS 25570, USNM 125009.

Distribution.—Russell County, Ala., Chattahoochee River: 

Broken Arrow Bend, right bank about 10 miles below Columbus, 

Ga., USGS 5348+6409; just below Burdock Landing, about 13.5 

miles below Columbus, USGS 848 (includes 1 figured specimen) 

+ 5386; Slick Bluff about 14 miles below Columbus, USGS 845 

+ 5387.

Chattahoochee County, Ga.: Chattahoochee River, Broken 

Arrow Bend, left bank, about 10 miles below Columbus, USGS 

847 + 6408 (figured); Upatoi Creek, 7 miles southeast of Columbus, USGS 5377 (includes 1 figured specimen); Ochillee Creek 

at old Ochillee, USGS 5378.

Superfamily MACTRACEA

Family MACTRIDAE

Genus CYMBOPHORA Gabb, 1869

Cymbophora ochilleana Stephenson, n. sp.

Plate 44, figures 1-3

Shell small, subtrigonal in outline, thin, subequilateral, equivalve, moderately inflated. Beaks prominent, incurved, prosogyrate, slightly separated, situated 

a little in advance of the midlength; umbonal area 

narrow. Anterodorsal and posterodorsal slopes steep, 

broadly excavated; umbonal ridge weakly developed, 

broadly subobtuse; greatest inflation central above the 

midheight, from which point the main surface rounds 

down broadly to the ventral margin. Dorsal margin 

broadly arched, anterior margin narrowly rounded, 

ventral margin very broadly rounded, posterior margin 

narrowly rounded a little below the midheight. Main 

surface contains very fine incremental lines that become 

a little coarser toward the ventral margin. On more 

than half of the anterodorsal slope bordering the margin 

the incrementals become sharp ridges; this ridged area 

is abruptly separated from the smoother surface on the 

slope above it. A similar ridged area is present on the 

posterodorsal slope where, however, it covers less than 

half of the slope.

Dimensions of the holotype, a right vajve: Length 

23.5 mm, height 19 mm, convexity 7 mm.

The hinge is not completely preserved in any of the 

available specimens; it is very thin and the calcareous

shell has become crystallized and is easily shattered in» 

the process of removing the matrix covering it. However, enough of the hinge can be seen in the type material to reveal most of its features. In the left valvetwo cardinal teeth below the beak are fused together 

at their upper ends and diverge widely below toward 

the interior; the posterior one is nearly direct and the 

anterior one oblique; a deep narrow channel separates 

the latter from the thin, sharp margin. The ligamental 

pit is internal back of the cardinal teeth but is poorly 

preserved. Well-developed elongated, thin laterals, 

one anterior and the other posterior are present; these 

are transversely striated on the sides in the direction of 

movement. The two cardinal teeth in the right valve 

are also fused above and diverge widely inward; the 

separating socket is wide enough to receive both the 

cardinals of the left valve. The laterals of the right 

valve are claspers receiving the single laterals of the 

left valve.

This species is similar in form to Cymbophora trigonalis Stephenson (1923, p. 336) from the Snow Hill 

marl member of the Black Creek formation of North 

Carolina. It differs in that the main surface lacks 

concentric ribbing and is marked only by fine incremental lines. The hinge features of the two species 

appear to be essentially identical.

Types.—Holotype, from the Eutaw formation, Ochillee Creek,, 

at old Ochillee, Chattahoochee County, Ga., USGS 15501, 

USNM 125000; 9 unfigured paratypes, same source, USNM 

125001; 1 figured paratype, same source, USGS 5374, USMN 

125002; 3 unfigured paratypes, same source, USNM 125003;

I figured paratype, same source, USGS 5378, USNM 125004;

II unfigured paratypes, same source, USNM 125005.

Distribution.—All the available examples are from Ochillee 

Creek, at the site of old Ochillee, Chattahoochee County, Ga., 

as recorded above under "types."

Range.—Known only from the basal beds of the Eutaw formation at the type locality.

Superfamily MYACEA 

Family CORBULIDAE

The family Corbulidae is represented in the Eutaw 

formation of the Chattahoochee region by many relatively large specimens referable to two or more species. 

One of these species, Caryocorbula? veatchi Stephenson,, 

n. sp., is closely related to Corbula oxynema Conrad 

(1875, in Kerr, app. A, p. 11), from the Snow Hill marl 

member of the Black Creek formation of North Carolina, and another, Caryocorbula! georgiana Stephenson, 

n. sp., is a species possessing a coarse type of concentric 

sculpture. Another probably undescribed species, represented by poorly preserved specimens, has still coarser 

concentric ribbing and is larger than the typical C. 

georgiana.

Yokes has shown (1945, p. 7-10) that the genotype
FOSSILS OF THE EUTAW FORMATION, ALABAMA-GEORGIA 245

of Corbula Lamarck (1799), C. sulcata Lamarck, a Recent 

species from the coast of Senegal, West Africa, posesses 

hinge characters sufficiently distinctive and characteristic to separate it generically from many of the Tertiary 

and Cretaceous species that have been referred to 

CorbuLi. I have examined a right and a left valve 

labeled C. sulcata Lamarck, presumably topotypes 

(USNM Ter. Coll. Moll. 614185), from the Senegal 

coast, and am in agreement with Yokes' conclusion. 

The characters on Lamarck's species that indicate this 

separation are, in the hinge of the left valve, the absence, 

of a chondrophore, the presence of a large cardinal tooth, 

the deep submergence of the ligamental pit (resilifer) 

and the separation of this pit from the adjacent socket 

by a thin septum and, in the right valve, the presence 

of a weak, but distinct, short posterior lateral tooth 

that fits into a shallow lateral socket in the left valve. 

For the purpose of comparison illustrations of a right 

and a left valve of the Recent C. sulcata Lamarck are 

given on plate 45, figures 1-6. The deep ligamental 

pit and the prominent cardinal tooth in the left valve, 

the lateral tooth in the right valve, and the corresponding lateral socket in the left valve are clearly shown in 

these illustrations.

A score or more of generic names have been introduced by Vokes and others for shells of the family 

Corbulidae, most of which at one time or another have 

been referred to Corbula. The species here described 

under the name, Caryocorbula? veatchi, appears to 

possess most of the essential generic features of Caryocorbula Gardner (1926, p. 46) from the Claiborne group 

(Eocene) of Alabama, and is referred questionably to 

that genus.

Genus CARYOCORBULA Gardner, 1926

1926. Caryocorbula Gardner, Nautilus, v. 40, p. 46.

1928. Caryocorbula Gardner, U. S. Geol. Survey Prof. Paper

142-E, p. 230. 

1945. Caryocorbula Gardner. Vokes, Am. Mus. Nat. History

Bull., v. 86, art. 1, p. 11.

Gardner designated Corbula alabamiensis Isaac Lea, 

from the Claiborne group (Eocene) as the type species 

of Caryocorbula and described the genus as follows:

Shell small or of moderate dimensions; acutely keeled posteriorly; 

slightly inequivalve; the right valve a little larger and a little 

higher relatively than the left; both valves concentrically 

rugose, the sculpture upon the right valve in some species 

stronger and more regular than upon the left; a microscopically 

fine radial lineation developed in some of the later species, 

particularly upon the posterior keel; ligament, dental, muscle 

and sinal characters similar [?] to those of Corbula s. s.

The Cretaceous species here referred questionably 

to Caryocorbula appear to be essentially like that 

genus in hinge, ligamental and internal features, but

they are plumper, more trigonal in outline, more 

pointed posteriorly and average larger.

The whole group of Cretaceous and Tertiary 

Corbulidae is in need of critical monographic study.

Caryocorbula? veatchi Stephenson, n. sp. 

Plate 44, figures 4-9

Shell of medium size, moderately thick, subtrigonal 

in outline, inflated centrally and anteriorly, compressed 

and subpointed posteriorly, rostrate on posterodorsal 

margin, very inequilateral, inequivalve, the right 

valve slightly larger and overlapping the left around 

the margins. Beaks moderately prominent, incurved, 

slightly prosogyrate, closely approximate, situated 

about 0.55 the length of the shell from the anterior 

extremity; right and left beaks of nearly equal height. 

Umbonal ridge weak but traceable as a thin, weak 

carina from the beak to the posterior extremity; on 

the right valve the space between this ridge and the 

dorsal margin is very narrow; on the left valve this 

space is slightly wider; it is slightly excavated on 

each valve.

Dimensions of the nearly complete holotype: Length 

20 mm, height 14 mm, thickness 11.6 mm. A paratype, 

a right valve, shown on plate 44, figure 6, measures: 

Length 21 mm, height 15.5 mm, convexity 6.7 mm.

The hinge of the right valve bears a strong, trigonal, 

pointed, upturned cardinal tooth, bordered posteriorly 

by a deep, wide resilial socket. On the left valve the 

chondrophore, which supports the ligament, is elevated 

and is separated from the posterior margin of the 

shell by a weak, narrow ridge; the middle of the 

chondrophore is slightly excavated. In front of 

the chondrophore is a deep trigonal socket for the 

reception of the cardinal tooth of the right valve. 

The adductor scars are slightly upraised; the posterior 

scar is bordered on the front side by a low, narrow 

ridge that, extended downward, coincides with the 

very shallow pallial sinus. On the inner surface 

of the right valve a narrow groove closely paralleling 

the margin marks the contact of the margin of the 

overlapped left valve. The surface is ornamented 

with fine, subdued, somewhat irregular growth ridges 

that are a little coarser toward the outer margins. 

Senility is indicated by the abrupt inbending of the 

outer surface within 1 to 4 millimeters of the ventral 

and anterior margins of adult shells.

Compared with the closely related Caryocorbula? 

oxynema (Conrad), from the Snow Hill marl member 

of the Black Creek formation of North Carolina, this 

species possesses a thicker shell, a heavier hinge, and 

a finer and weaker pattern of concentric growth ridges.

Types.—Holotype, from Ochillee Creek at old Ochillee,
246 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

Chattahoochee County, Ga., USGS 5374, USNM 125036; 

2 unfigured paratypes, same source, USNM 125037; 2 figured paratypes, same source, USGS 15501, USNM 125038; 

14' unfigured paratypes, same source, USNM 125039; and 3 

unfigured paratypes, same source, USGS 5378, USNM 125040.

Named in honor of Otto Veatch, the original collector, and 

one time assistant State Geologist of Georgia.

Distribution.—Alabama, Russell County: Broken Arrow Bend, 

Chattahoochee River, right bank, USGS 5384.

Georgia, Chattahoochee County: Broken Arrow Bend, Chattahoochee River, left bank, USGS 847; Ochillee Creek near old 

Ochillee (type locality), USGS 5374 + 5378+15501 + 25569.

Range.—Lower part of Eutaw formation, Chattahoochee area, 

Georgia-Alabama. Closely related large shells belonging to 

two or more species of Caryocorbula1! are present at a higher 

stratigraphic position in the Cusseta sand (Alabama-Georgia) 

and in the Snow Hill marl member of the Black Creek formation 

of North Carolina.

Caryocorbula? veatchi longa Stephenson, n. var. 

Plate 44, figures 10-13

This shell from the upper part of the Eutaw formation resembles Caryocorbula? veatchi but it averages a 

little larger, is proportinately longer, and is not quite 

so strongly inflated; its concentric surface sculpture, 

though weak and moderately fine, is nevertheless 

stronger than that of C.? veatchi; the features of the 

chondrophore in the left valve are more strongly 

marked.

Dimensions of the holotype, a right valve: Length 

23 mm, height 15 mm, convexity 6.5 mm.

Types.—Holotype, a right valve, from Hurtsboro-Marvyn 

road 5.9 miles south of Lee County line in Russell County, Ala., 

USGS 25567, USNM 125041; 1 figured paratype, same source, 

USNM 125042; 8 unfigured paratypes, same source,- USNM 

125043.

Distribution.—In addition to the type locality (USGS 25567) 

poorly preserved specimens of the species have been identified 

from two localities on the Chattahoochee River in Russell 

County: just below old Burdock Landing, USGS 848, and at 

Slick Bluff, USGS 845+5387. Shells of comparable size but 

still more elongated, and having still stronger concentric sculpture occur at higher stratigraphic positions in the Blufftown 

formation and in the Cusseta sand.

Range.-—As here restricted this variety is known only from 

the upper pert of the Eutaw formation in Russell County, Ala.

Caryocorbula? georgiana Stephenson, n. sp. 

Plate 44, figures 14-16

Shell of medium size, subtrigonal in outline, strongly 

inflated centrally and anteriorly, humped in the anteroumbonal region, compressed and narrow posteriorly, 

inequilateral, inequivalve, the right valve slightly 

larger than the left. Beaks prominent, strongly incurved, prosogyrate at the tips, closely approximate, 

situated about centrally. Umbonal ridge of the right 

valve narrow, sharply defined, sinuous, paralleled on

the marginal side by a narrow radial excavation and on 

the other side by a broad radial excavation. Anterodorsal slope of right valve steep, overhanging near the 

beak; posterodorsal slope also overhanging a little near 

the beak. Anterodorsal margin broadly arched, anterior margin evenly rounded, narrower than a semicircle, 

ventral margin broadly rounded, posterior margin with 

a short truncation below midheight, posterodorsal 

margin straight, strongly inclined forward.

The main surface of the right valve bears concentric 

ridges that are small and fine in the umbonal area and 

increase in strength and coarseness outwardly, becoming very coarse adjacent to the ventral margin; these 

ridges are round crested and bear fine growth lines on 

the sides and in the interspaces; the ridges become 

smaller and much finer on the dorsal slopes. The surface of the left valve is not preserved on the available 

material, but imprints of small areas indicate that this 

valve lacks coarse ribbing and bears only small incremental ridges.____

Dimensions of the holotype, a right valve: Length 17 

mm, height 13 mm, convexity about 6 mm. Individuals may attain a length of 20 mm.

The hinge of the right valve includes one prominent, 

upcurved, trigonal cardinal tooth back of which is a 

deep, broad resilial depression; in front of the cardinal 

tooth is an oblique channel opening inward. Lateral 

teeth are wanting. A rubber impression made from the 

internal mold of a left valve (pi. 44, fig. 16) shows that 

the internal ligament is seated on a raised chondrophore 

directed obliquely to the rear and inward; in front of the 

chondrophore is a deep, wide socket for the reception of 

the cardinal tooth of the right valve. The adductor 

scars occupy raised platforms the impressions of which 

are conspicuous on internal molds; the posterior platform is a little higher than the anterior one. The pallial 

sinus is very shallow.

In the clay facies of the Eutaw formation exposed on 

Chattahoochee River at old Burdock Landing and at 

Slick Bluff, Russell County, Ala., are many internal and 

external molds of Caryocorbula? that have the form and 

outline of C.t georgiana, but average larger and show a 

wider range in individual variation in the coarseness of 

their concentric sculpture. Most of them are flattened 

and distorted by mechanical pressure. They are 

referred questionably to C.I georgiana.

Types.—Holotype, from Ochillee Creek south of bridge at old 

Ochillee, Chattahoochee County, Ga., USGS 15501, USNM 

125044; 1 figured paratype, same source, USNM 125045; 1 

figured paratype, same source, USGS 5378, USNM 125046; 28 

unfigured paratypes, same source, USNM 125047; 12 questionable examples from just below old Burdock's Landing, Chattahoochee River, Russell County, Ala., USGS 848, USNM 125048.

Distribution.—Ochillee Creek near old Ochillee, Chattahoochee
FOSSILS OF THE EUTAW FOKMATION, ALABAMA-GEORGIA 247

County, Ga., USGS 5378+15501; Broken Arrow Bend, Chattahoochee River, left bank, USGS 847; questionably on Chattahoochee River, right bank just below old Burdock Landing, 

USGS 848; questionably on Chattahoochee River, right bank at 

Slick Bluff, USGS 845 + 5387.

Range.—The types and duplicate specimens are from the 

lower part of the Eutaw formation in the Chattahoochee River 

area, Georgia-Alabama; questionably identified specimens are 

present in the upper part of the formation.

Class CEPHALOPODA

Order AMMONOIDEA

Family PLACENTICERATIDAE

Genus PLACENTICERAS Meek, 1870

Placenticeras benningi Stephenson, n. sp.

Plate 44, figures 21, 22; plate 45, figures 7-11

The species, as seen in the holotype and 15 paratypes, 

attains medium size for the genus; all the paratypes are 

smaller than the holotype. Shell strongly involute, 

compressed on the flanks, with greatest inflation of the 

volution at the umbilical shoulder, the flanks converging outward toward the venter. In early stages the 

flanks are nearly flat but as growth proceeds they become broadly convex in profile. The flattened venter 

is narrow for the genus. In young stages retaining the 

shell the venter is slightly excavated and is bordered on 

each ventral angle by a very thin upraised rim. At a 

radius of 35 to 50 mm the venter begins to become 

rounded. In some of the smaller stages this rounding is 

accompanied by a smoothing out of the surface, apparently indicating maturity at an earlier stage than that 

attained by the holotype. Beginning at a radius of 

about 55 mm on the holotype a row of small obscure 

elongated nodes 8 to 10 mm apart on each ventral 

angle can be detected; this part of the venter is considerably watei-worn. These nodes are wanting on the 

younger paratypes whose venters become rounded at 

early stages.

The umbilicus is small with steeply sloping sides; the 

umbilical shoulder is at first obtusely subangular but 

becomes rounded in adults. In early stages a succeeding whorl envelops three-fourths or more of the preceding whorl, but in later stages only about two-thirds of 

the preceding whorl is enveloped. In young shells the 

flanks of the whorls are nearly smooth but they exhibit 

a row of gentle radially elongated undulations about 

two-fifths the width of the flank inward from the 

ventral angle; these increase in strength forward and 

they increase in spacing from 5 mm apart on early 

stages to 20 mm or more apart on adults; they do not 

develop into nodes proper. At a diameter of 65 mm 

or less weak nodes begin to appear on the umbilical 

shoulder; at first these are spaced 12 to 15 mm apart 

but in the forward direction the spacing increases to 20

to 24 mm on adults, and the nodes increase in size to 

moderate prominence.

The sutures are best seen on several of the young 

paratypes; the description is based on the one shown in 

plate 44, figure 21. The ventral lobe is broad and 

shallow with a pair of short digitate diverging prongs, 

one on either side; these prongs inclose a broad, short 

ventral saddle which is divided by a relatively broad 

very shallow lobule. The first lateral saddle is relatively 

very broad and short and is subdivided by four short 

bifid subsaddles, separated by three small sublobes; the 

subsaddles and sublobes are further indented with tiny 

lobules. The first lateral lobe is narrow and trifid, the 

sublobes are indented with lobules. The second lateral 

saddle is less than half as broad as the first, is bifid with 

sublobes, and is further indented with lobules. From 

the venter to the line of involution there are 11 saddles 

separated by 10 lobes, both saddles and lobes becoming 

simpler inward; the last saddle at the line of involution 

is quite small and plain. The third lateral lobe inward 

from the venter is larger than any of the others. The 

inner part of the suture beyond the line of involution is 

not uncovered.

The holotype, chosen for its size (pi. 45, fig. 7), has 

suffered considerable mechanical compression and some 

distortion, especially the part representing the living 

chamber. The measurements that can be given are 

therefore only approximate and include the following: 

Maximum diameter 170 mm, maximum radius center to 

venter 103 mm; at a diameter of about 120 mm the 

transverse diameter of the volution is about 35 mm; at 

the same diameter the height of the volution from the 

line of involution to the venter is about 52 mm. A 

more accurate measurement of the young paratype 

shown in plate 44, figure 21, can be made as follows: 

Greatest diameter 87 mm; maximum radius center to 

venter 50 mm; height of volution line of involution to 

venter about 40 mm; transverse diameter between nodes 

21 mm; same on nodes 25 mm; maximum diameter of 

umbilicus measured shoulder to shoulder 30 mm; the 

same measured line of involution to line of involution 

20 mm.

This species is closely related to Placenticeras guadalupe (Roemer) from the Austin chalk (Inoceramus 

undulatoplicatus zone) at the Falls of the Guadalupe, 2 

miles below the highway bridge at New Braunfels, Tex. 

(Roemer, 1852, p. 32, pi. 2, fig. 1 a, 6.) Compared with 

the illustrations of Roemer's species this species is more 

compressed, the nodes on the ventral angles are much 

weaker or absent, and instead of a row of nodes on the 

outer flank it possesses a corresponding row of undulations and this row is a little farther removed from the adjacent paralleling ventral angle; the saddles and lobes of 

the suture also seem to be consistently shorter. The
248 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY

specimen referred by Hyatt (his collection) to Roemer's 

species (Hyatt, 1903, p. 197, pi. 29), as figured, does not 

.appear to be correctly identified. Compared with 

Roemer's figured specimen it shows no indication of the 

presence of a row of small relatively closely spaced nodes 

on each ventral angle and on the adult stage the shoulder 

nodes become much larger, elongated and directed 

obliquely forward.

Placenticeras sancarlosense Hyatt (1903, p. 200, pi. 

30; pi. 31, figs. 1,2), from San Carlos, Presidio County, 

Tex., is also nearly related to P. benningi, but it is 

stouter, more closely coiled, possesses a row of nodes 

instead of undulations on the outer flank, and has well 

developed alternating nodes on the ventral angles at an 

early stage (diameter of 40 mm or less).

Assuming that all the specimens here referred to 

P. benningi are correctly identified there is considerable 

individual variation of form within the species. Some 

of the younger shells begin to thicken and round over on 

the venter, at the same time becoming smoother on the 

venter and outer flank, than is true of the holotype 

which represents a much later and larger stage of 

growth.

Types.—Holotype, from basal beds of Eutaw formation 

Broken Arrow Bend, Chattahoochee River (Alabama side) 

USGS 5384, USMN 125049; 1 figured paratype, from the same 

zone on Upatoi Creek, 7 miles southeast of Columbus, USGS 

5377, USNM 125050; 2 figured paratypes from same zone, 

on Ochillee Creek, old Ochillee (below bridge), Chattahoochee 

County, Ga., USGS 15501, USNM 125051; 2 unfigured paratypes, 

same source, USNM 125052; 6 unfigured paratypes, same source, 

USGS 25569, USNM 125053; 4 unfigured paratypes from old 

Ochillee (upstream from bridge), USGS 25570, USNM 125054.

Named in honor of Brig. Gen. Henry L. Benning, a distinguished Confederate Army officer for whom Fort Benning was 

named, and whose home was in Columbus, Ga.

Distribution.—The known occurrences of this species in the 

Chattahoochee region are recorded under the heading "types" 

above.

Range.—The species is known only from the basal beds of the 

Eutaw formation in the Chattahoochee region.

REFERENCES

Berry, E. W., 1923, The age of the supposed Lower Cretaceous of

Alabama: Washington Acad. Sci. Jour., v. 13, no. 20, p.

433-435. 

Conrad, T. A., 1860, Descriptions of new species of Cretaceous

and Eocene fossils of Mississippi and Alabama: Acad. Nat.

Sci. Phila. Jour., 2d ser., v. 4, p. 275-298, pis. 46, 47. 

———— 1875, Descriptions of new genera and species of fossil shells

of North Carolina, in Kerr, W. C., Physical geography,

resume, economical geology, N. C., Geol. Survey Rept., v.

1, app. A, p. 1-13, pis. 1, 2. 

Dall, W. H., 1898, Contributions to the Tertiary fauna.of Florida:

Wagner Free Inst. Sci. Trans., v. 3, pts. 1-6, 1654 p., 60 pis. 

D'Orbigny, Alcide, 1843-47, Description des animaux invert6-

bres; Lamellibranches: Paleontologie francaise, terraine cr6-

tace, 1st ser. v. 3, 807 p. pis. 237-489.

Eargle, D. H., 1950, Geologic map of the Selma group in eastern

Alabama: Oil and Gas Investigations, preliminary map 105

(with text). 

Gardner, Julia, 1926, The nomenclature of the superspecific

groups of Corbula in the lower Miocene of Florida: Nautilus,

v. 40, no. 2, p. 41-46. 

Hyatt, Alpheus, 1903, Pseudoceratites of the Cretaceous: U. S.

Geol. Survey Mon. 44, 351 p., 47 pis. 

Langdon, D. W., 1890, Variations in the Cretaceous and Tertiary

strata of Alabama: Geol. Soc. America Bull., v. 2, p. 587-606. 

Lea, Isaac, 1833, Tertiary formation of Alabama, in Lea, Isaac,

1833, Contributions to geology, Phila., 227 p., p. 29-208,

pis. 1-6. 

McCallie, S. W., 1903, Sandstone dikes near Columbus, Georgia:

Am. Geologist, v. 32, p. 199-202. 

Meek, F. B., 1873, Preliminary paleontological report, consisting

of lists of fossils with descriptions of some new types: U. S.

Geol. Survey Terr. 6th Ann. Rept., p. 429-518.

———— 1876, A report on the invertebrate Cretaceous and Tertiary fossils of the Upper Missouri country: U. S. Geol. 

Survey Terr., 9th Ann. Rpt., 629 p., 85 figs., 45 pis.

Monroe, W. H., 1941, Notes on deposits of Selma and Ripley age 

in Alabama: Ala. Geol. Survey Bull. 48, 150 p.

———— 1947, Stratigraphy of outcropping Cretaceous beds of 

southeastern United States: Am. Assoc. Petroleum Geologists Bull., v. 31, no. 10, p. 1817-1824.

Monroe, W. H., Conant, L. C., and Eargle, D. H., 1946, PreSelma Upper Cretaceous stratigraphy of western Alabama: 

Am. Assoc. Petroleum Geologists BulL, v. 30, no. 2r p. 

187-212, 4 figs.

Roemer, Ferdinand, 1852, Die Kreidebildungen von Texas und 

ihre organischen Einschltisse, Bonn, bei Adolph Marcus,, 

100 p., 11 pis.

Stephenson, L. W., 1911 [1912], Cretaceous [of Georgia], in 

Veatch, Otto, and Stephenson, L. W., Geology of the 

Coastal Plain of Georgia, Ga. Geol. Survey BulL, no, 26, 

p. 66-215.

———— 1914, Cretaceous deposits of the eastern Gulf region: 

U. S. Geol. Survey Prof. Paper 81, 77 p., 21 pis.

———— 1923, The Cretaceous formations of North Carolina; 

pt. 1, Invertebrate fossils of the Upper Cretaceous formations: N. C. Geol. and Econ. Survey, v. 5, 592 p., 100 pis.

———— 1936, New Upper Cretaceous Ostreidae from the Gulf 

region: U. S. Geol. Survey Prof. Paper 186-A, p. 1-12, pis. 

1-3.

———— 1937, Stratigraphic relations of the Austin, Taylor, and 

equivalent formations in Texas: U. S. Geol. Survey Prof. 

Paper 186-G, p. 133-146, pi. 44, fig. 7.

1941, The larger invertebrate fossils of the Navarro group

of Texas: Tex. Univ. Pub., Bull. 4101, 641 p., 95 pis. 

Stephenson, L. W., and Monroe, W. H., 1938, Stratigraphy of

Upper Cretaceous series in Mississippi and Alabama: Am.

Assoc. Petroleum Geologists Bull., v. 22, no. 12, p. 1639-

1657. 

———— 1940, The Upper Cretaceous deposits [Mississippi]:

Miss. State Geol. Survey, Bull. 40, 296 p., 15 pis. 

Veatch, Otto, 1909, Second report on the clays of Georgia: Ga.

Geol. Survey Bull., no. 18, 453 p. 

Vokes, H. E., 1945, Superspecific groups of the pelecypod family

Corbulidae: Am. Mus. Nat. History Bull., v. 86, art. 1, p.

1-32, pis. 1-4. 

Woods, Henry, 1904-12. A monograph of the CretaceousLamellibranchia of England: Palaeont. Soc. Mon., v. 2,.

pts. 1-9, 473 p., 62 pis.
INDEX

[Italic number? indicate descriptions]

Acknowledgments___——_ — — _ — — — ._..___.......__.._.....__ 228

alabamiensis, Corbula. __-----------.,.-______...____--.-..._._ 245

Ostrea.-------- ___------___....._.________________________ 239

Ammonoidea..-----_____________.______.______.__ 247

Anchura— _.-----_______________________________....._. 231

anomala, Avicida.-----------...-------------_._______._.--._--------- 237

Anomia olmstedi.---.--.-- ___._-_____--..___--.._____--._._ 242 

preolmstedi—- ———.-- — —-———-—— 230, 231, 232, 234, «#; pi. 41

sp. — — — — — - — --•—- — — ———— ————— ———— — ——— 232

Anomiacea.—.—— —____—._.__.__--___..._.___-. _.____ 242

Arcacea..___..._________._______________ .-- ____ 235

nucella, Gryphaea.. ___________________________„.____ 240

Austin chalk....___________________.__________.___ 234

A.ricula anomala------ _____---------____._____---__..--___ 237

B 

benningi, Placenticeras—-------------------------- 230, 231, 232, 234, $47, 248; pl.44

Black Creekformation.....-——--—————- 234, 235, 236, 243, 244, 245, 246

Blufftown formation.. —— .— __.________.._._... 229, 232, 233, 234, 240, 242, 243, 246

Breviarca congesta. ——-- —— --- — ___--.----_--.-----—---------------------- 236

peroralis-...-_________________._______— _____ 236

awfitn/fato—— ——— ————— — ——————— ——— 234, 236; pi. 39

suboralis-------- ___.______.__-_____-_____________ 236

symmetros---------------... ------__----____.-__________________ 234

umbonata.---------...___-_______--_.___--___---------- 236

sp_._----—--.- — -- — -——-------—.- — -—.._--_-. 234, 2S6; pi. 40

Broken Arrow Bend, fossils from... ———————_.__.____._---_- 230

Burdock Landing, fossils from_-_-____.._.____.--_____-___._ 230

(Camptonectes) Pecten.--------...__. — — — .—__....______.____— _ 231

•Cardiaeea.. ___---------___-------__.__„_-----__--__— — ____ 242

Cardium.-.-__----_____-________________________-.- 231, 232

Cardium (Trachycardium) carolinense-..-_--_-_..-____..____.. 243 

ochitteanum------- ...-----_.__-_-_-_-__--_______------ 242; pi. 41

•carolinense, Legumen....————.___..——________ 230, 231, 234, 24S; pi. 44

carolinense, Cardium (Trachycardium)----------__-...- ——._-.------_-_--.-- 243

Caryocorbula..--------- ...— — —— — — — — —___-..-_______-__. $46

georgiana——- —------- — ---——-— —— ————- 230, 234, 244, 846; pi. 44

oxynema-..-------------... _-_-____-__-_------_...____._____ 245

veatcM.- —— — — — —— —---——— — - — -- 230, 231, 244, 846, 246; pi. 44

Caryocorbula veatchi longa-.--——_._.-_.__-._____—.....__ 232, 246; pi. 44

•centerensis, Ostrea ______....___--------------------__.__ —. 234

Clay section at Slick Bluff————— — ————————————————— 228

•congesta, Breviarca------------------ ____-------------_---------__.__ 236

Corbula alabamiensis-. __-._._-___..._-_______..._.___...... 245

oxynema........ . ——————...___._ —__________________ 244

sulcata.--.------—---- — — -......____.__.____________ ^45; pi. 45

•Corbulidae..__---_____.________________.________ 244 

Creek Stand, fossils from near...__-__----------________..._...... 233

•cretacea, Ostrea-— — ——...———————— 228, 230, 231, 233, 234, 239, 240; pis. 40, 42 

Cussetasand-—--—— —————-—. — -——————————— 234, 243, 246

Cymbophora ochitteana,------------ __-____-_-.-_-__-----.___. 231, 244; pi- 44

trigonalis-.-.- ...----_........___.__.._____.._.__..____.. 244

42yprimeria.---------_._--.--.__...._......_...__......._...... 231

depressa--.-------...--...____..._.__._......_.________.. 230

sp..__-------_____.__________________..._____ 232

D 

depressa, Cyprimeria--..-.......___--------__.......________.. 230

E 

Etea———__———-—._.—__—————— —— — ——————— 231

Eutaw fauna and its relationships.------------- —— -------- ——...——.—— 234

Eutaw formation..- ———. —————— — -. — -- — — — --- —— ———— 227 

localities..-------------------------.------------------------------------- 228

---------------------------------------------------------------- 232, 233

ponderosa------_-__-_... ——— „—————————————————— 235, 243

tigrina,.....--___.- — — _._—— —. —— ———— —— —— — - ——. — ——— 234

Mpo/oiensw.--.-------..-----—--------------------- 230, 231, 234, 84!; pi. 43

sp———— ————— — — ——— — —— —.-———————— 232,234

Fort Decatur, fossil plants from. _._. — -——— —— .. — — - —— ——— .._- ——— 231

G

Gardner, Julia, quoted— .... — _ — ——————————————— - ———————— 245

georgiana, Caryocorbula--------- ------------------------ 230, 234, 244,^6; pi. 44

Gordo formation of Tuscaloosa group ___ ——— — . —————— - ————— 228, 231 

--------------------------------------------------------------- 233

aucella _ _ — — _— — .. _ .. — — . — _ — -- —— — —— - — - — — — — — 240 

— -—-—- — — .—— - ——— ————•—————— 234, ##), 241; pi. 41

Idonearca---.- ————....———————————— ———————————— ———— 231

inflata, Trigmarca...—-.——-----—--- — --—--------------- 234, 237; pi. 40

Inoceramus undulatoplicatus-.- — —————— —..__.. —. —— _—- —— ——.. 234, 247

sp._-_ ——— — — ———— — ——— ——— —— — —— — — — ——— ——— — 232

Legumen carolinense--—------------------------------- 230, 231, 234, 24S; pi. 44

Leptosolen.--------- ——.. — — — — — — —— — —— — — —— ———— —— — —— 231

Liopistha sp___. —— —.— — — — —— — — ———.. —— — _. — —— —— — —— ——— 232

List of fossils---------------------------------------------------------- 234

Location of most important fossil-bearing strata_._- —— ——.. —————— 229

longa, CarycorbuJa veatchi-—------- —— — -_— ———— ——. —— —..—— 246; pi. 44

(Lopha) ucheensis, Ostrea.. ._——————————————————— 230, 238; pi. 43

M

McShan formation.__._-———_—- —— —. — ———————— —————————— 227 

maconensis, Trigonarca———... — —— ——. — —————- ——— ----------—— 237

Mactracea....... — ——— — ——————. —— ——— —— ———— ——..———— 244

Mooreville chalk——— ————————— — —— 227, 228, 233, 234, 239, 240, 241, 242

Myacea.--__--__.——_— ———__. — — —..... — ——...—————— 244

N

Nuculaprepercrassa-.--. ————————————— ——————————— — 834, 235; pi. 39 

Nuculacea.———. —— ——————. —— —._. —— —— ——— —————————.. 234

O 

obliqua, Protarca—--———— ——————————————— 231, 234, 235; pi. 35

ochilleana, Cymbophora---------------.------------------- — - 231,342,^4; pi. 44

ochitteanum, Cardium (Trachycardium).---- — - ——... —— — —— -------- 242; pi. 41

Ochillee Creek, fossils from.,_____...___-.—__—————-—-——— 231 

olmstedi, Anomia. _ — —— —— —— —-.-_ — ——— ——— —... —— ——.. ——.. 242

Ostracea....—.. — -_-.—. —— — --- — .-- — --- —— — - ——— --.-——— 238

Ostrea alabamiensis...————— ———— ——— - — — — - —— - —— —————- 239 

centerensis-- —— --.... — ——— ——... —— ———.... ————— ———.— 234

cretacea----—— ——.....——— ———— 228,230,231,233,234,#30, 240; pi. 40

travisana. —————.. —. — - ———————— —— ————— —————————— 234

ucheensis.-.-—.—-——————.————————————— 230,232,233

249
250 INDEX

Page 

Ostrea cretacea zone--- — — -—.— — — — — ———-_ — — — — -_ ——— — — — — — ____ 228

Ostrea (Lopha) ucheensis-...................... _______ _ _________ _ 230, 838; pi. 43

Owl Creek formation- —_. — — ______ — — — _____—__-_ — __-—___________—_ 235

i-rynema, Caryocorbula-.-..........................................._......... 245

Corbuta.-..... — ......................................................... 244

Pecten (Camptonectes) _______________________________________________________ 231

perovalis, FSreriarca ______-_--_____--___-_-___-__ — __—.____ —______ 236

Pholadomya---. ____________________________________________________________ 231

Placenticeras benningi. _____________________________ 230, 231, 232, 234, ,, 248; pi. 44

quadalupe----------------------------------------------------------------- 247

sancarlosense---.------------------------- _________________________________ 248

PUcatida— —......_-___ —— - ——— —— _____________________________ 233

ponderosa, £.ro^!/ra__________________________________________________________ 235,243

preolmstedi, Anomia........ __________________________ 230, 231,232, 234, .;#; pi. 41

prepercrassa, ATWCM?<Z_ —__.__—__--___.---- — __ — --__--____ —__ _ ____ 234, 235; pi. 39

Protarca obligua..... ___________________________________________ 231,234,235; pi. 39

Pseudoptera _______— — _ — _—— —_________-------______________________ 237

securiformis.--------~--------... ____________________ 230,231,233,234,238; pi. 40

Pteriacea._-_ — — _______-___.__________________________________________ 237

References—---------------- ________________________________________ 228,248

Ripley formation. ———- —___ — _—_____ — __—__ — _— — _____________________ 235

S 

sancarlosense, Placenticeras-- — ----*------------------------------------------ 248

Santonian age — —— - — —- — -- — - — - — — --- — ——- — - — --- — ---- — - — _ — — — — 234

Sections, description of, Broken Arrow Bend. __-_---______._____________'___ 229, 230

Burdock Landing__ — — — — _— —_ — — — _--—— __ — ___ _____— __.__ 229,230

-east by north of Hardaway station—— —__- —- — - — __- —— — — — _- — _-_—_ 233

Hurtsboro-Marvyn road, south of Lee County line.______________________ 232

near Vchee--------------------------------------------------------- __.. 232

north of Creek Stand..__________.-___________________________ 233

OchilleeCreek___----___ __________________________________________________ 231

Slick Bluff.-----------____-___-_-_------_-_-.____-----------.__________ 229,230

southwest of Phenix City...------------------------__------_-_---__-.__-_ 231

southwest of Youngs Bridge____----_-_-______.____-___-____________ 232

Uchee Creek valley--_-_-_--______----__--____-__--_______________________ 232

Upatoi Creek-___----_-_----____---__-___----.__________________________ 230, 231

:8elma group..____------______________-----________________.______________ 227,239

securiformis, Pseudoptera---.--------------- _____-_-.______.___ 230, 231, 233, 234

JSerpula ________-__..._.____........................ ______________ 231

Page 

Slick Bluff, fossils from.--.--_-----____-_--------____.. — _._ — __ 230

Snow Hill marl member---._-__----------------_------ 234,235,236,243,244,245,246

Stratigraphic section, east by north of Hardaway station.____.--_-_______-_-_- 233

Ochillee Creek....--.--.--_---.---------------------- — _-------- 231

old Marvynroad, northwest of Uchee. __----------------_- — _________ 232, 233

Society Hill road, north of Creek Stand_-__----_--------_-__-------------- 233

Upatoi Creek____________.________-.--_------------------------------ 231

Stratigraphic setting...------------------------------------------------------- 228

submflata, Breviarca.................................................. 234,^35; pi. 39

,mbovalis, Breviarca------.----------------------------------------------------- 236

sulcata, Corbula-.------------------------------------------------------- 245; pi. 45

symmetros, Berviarca—-------------------------------------------------------- 234

Te?Hno__.--—---- — ------- — — — — — - — — — — --——-—— 231

figrina, Exogyra.-------------------------------------------------------------- 234

Tombigbee sand member______..__----___------------ 227,228,239,240,241,242

(Trachycardium) carolinense, Cardium..------------------------ — - — --__-_-_ 243

ocMlleanum, Cardium... —..... —— . — — ---.-.--.- — - — ------- — __ «4«; pi. 41

travisana, Ostrea,------------------------------^------------------------------ 234

trigonalis, Cymbophora-.--------------------- — _--__-___-_._ —— _______ — _. 244

7Yi0o.ia.ca-_---------------------------------------------------------------- 231,232

inflata—— — - — - — — - — — ---- — — — — — - — — -- 232,234,#37; pi. 40

maconensis---------------------------------------------------------------- 237

rw..i.e«a-------------------------------------------------------------------- 231

Tuscaloosagroup---------.--.------- —------------------------ 228,230,231

U 

Uchee, fossils from near. _________--__--__-__---_---------_-----------------_- 232

ucheensis, Ostrea.----------------- —-------------------------- 230,232,233

(Lopho).------- —---------------------------------------- 230,#38; pi. 43

umbonata, Bremarca. ——-__-_ — _ — --------------------- —._ — -_ — — — — — — 236

undulatoplicatus, Inocerarmis------------------------------------------------ 234, 247

Upatoi Creek, fossils from..-.--------------------------------------------- 230-231

u,patoinensis,Exogyra------------------------------------- 230, 231, 234,«#; pi. 43

veatchi, Caryocorbida——----.-------- — — . — .-. 230,231,234,244,^5,246; pi. 44

veatchilonga, Carycorbula-—----------------------- — — - — ---------- 232,#45; pi. 44

Veneracea.------------------------------------------------------------------- 243

VoliLtomorpha----.------------------------------------------------------------ 231

wratheri, Gryphaea............... — — — — — —— ——— — — 234,#40, 241; pi. 41

Youngs Bridge, fossils from near_- — - ———— — — ---- — ------ — ——— -- 232

U. S. GOVERNMENT PRINTING OFFICE: I9S3
PLATES 38-45
PLATE 38

A, The unconformable contact of the Eutaw formation on the Gordo formation (Tuscaloosa group) in a cut of the old ColumbusSeale road (near the present U. S. Highway 431) about 4 miles southwest of Phenix City (opposite Columbus, Ga.) in Russell

County, Ala. 

B, Light-gray silty, micaceous shale of the upper part of the Eutaw formation exposed in Slick Bluff on Chattahoochee River, right

bank, about 14 miles below Columbus, Ga. 

C, Layers of nodular calcareous, fossiliferous concretions in dark-gray sandy marine clay in right bank (Alabama side) at Broken

Arrow Bend, Chattahoochee River, about 10 miles by the river below Columbus, Ga. 

D, Calcareous fossiliferous sandstone in the bed of Ochillee Creek below the mill dam at the site of old Ochillee, about 10 miles

southeast of Columbus Ga.; the dam and mill have disappeared and the creek is now crossed at this place by a bridge of one

of the roads of the Fort Benning Military Reservation.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 38

:&W$&i 'i*V!»*j£L. i ^.

VIEWS OF THE EUTAW FORMATION IN THE CHATTAHOOCHEE REGION
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 39

NUCULA, BREVIARCA, AND PROTARCA
PLATE 39

[Figures natural size except as indicated]

FIGUBES 1-5. Nucula prepercrassa Stephenson, n. sp. (p. 234).

1. Left valve of a paratype. USGS 15501, USNM 125059. 

2, 3. Side and top views of the holotype, a right valve. USGS 15501, USNM 125058.

4. Interior view, X 1/4, of holotype.

5. Internal mold, X 1%, of a paratype, a right valve. USGS 5378, USNM 125061. 

6-8. Breviarca subinflata Stephenson, n. sp. (p. 236).

Views, X 3, of the holotype, a left valve. USGS 15501, USNM 125067. 

9-14. Protarca obliqua Stephenson (p. 235).

9, 10. Exterior and interior views of a plesiotype, a left valve. USGS 15501, USNM 125064.

11. Exterior view, X 1& of a plesiotype, a young right valve. USGS 5378, USNM 125063.

12. Internal mold of a plesiotype, a left valve, from the same source. USNM 125063.

13, 14. Views of a large plesiotype, a left valve, from the Cusseta sand near Peachburg, Ala. USGS 25478, USNM 

125062. (Inserted for comparison.)
PLATE 40

[Figures natural size except as indicated!

FIGURES 1, 2. Breviarca symmetros Stephenson, n. sp. (p. 236).

Views, X 3, of the holotype, a left valve. USGS 25567, USNM 125070. 

3. Breviarcat sp.

View of left valve, X 3. USGS 15501, USNM 125072. 

4-8. Trigonarca inflata Stephenson, n. sp. (p. 237).

4. A paratype, a juvenile right valve. USGS 25567, USNM 125074.

5. Interior view, X 2, of the preceding shell.

6-8. Views of the holotype, a left valve. USGS 25567, USNM 125073. 

9, 10. Pseudoptera securiformis Stephenson, n. sp. (p. 238).

9. The holotype, a left valve. USGS 15501, USNM 125076.

10. A paratype, a left valve, mechanically deformed, showing details of sculpture. USGS 25570, USNM 125082. 

11, 12. Ostrea cretacea Morton (p. 239).

11. Interior view of a plesiotype, a left valve. USGS 17007, USNM 125027.

12. Exterior view, X l/z, l of a left valve, uncoated to show color bands. USGS 18308, USNM 125029.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 40

BREVIARCA, TRICON ARCA, PSEUDOPTERA, AND OSTREA
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 41

13 14

CARDIUM (TRACHYCARDIUM), GRYPHAEA, ANOMIA, AND PSEUDOPTERA
PLATE 41

[Figures natural size except as indicated]

FIGURES 1, 2. Cardium (Trachycardiuni) ochilleanum Stephenson, n. sp. (p. 242).

1. View, X 1/2, of a paratype, a left valve. USGS 15501, USNM 125012.

2. View, X ll/z, of the holotype, a right valve. USGS 15501, USNM 125010. 

3-8. Gryphaea wratheri Stephenson (p. 240).

3. Left valve of a large plesiotype. USGS 6442-B, USNM 125024.

4. Left valve of a plesiotype, showing a posterior wing extension. USGS 19060, USNM 125022.

5. Left valve of a plesiotype lacking posterior wing extension. USGS 17576, USNM 125023.

6. Right valve of a plesiotype from the same source. USNM 125023.

7. Interior view of the preceding shell.

8. Interior view of the shell shown in fig. 5. 

9-11. Anomia preolmstedi Stephenson, n. sp. (p. 242).

9. Exterior of holotype, a left valve. USGS 6409, USNM 125014. 

10, 11. Exterior and interior views of a paratype from the same source; the interior view shows the imprint of the

byssal opening (foramen) of the right valve on matrix filling, USNM 125015. 

12-14. Pseudoptera securiformis Stephenson, n. sp. (p. 238).

12, 13. Rubber casts from internal molds (paratypes) of left valves, showing hinge areas. USGS 5384, USNM

125081. 

14. Right side of internal mold (a paratype), showing flattish form of right valve. USGS 5377, USNM 125080.
PLATE 42

All figures natural size] 

FIGURES 1-17. Ostrea cretacea Morton (p. 239).

1-2. Topotypes, left valves, from Erie Bluff, Warrior River, Ala. USGS 6428, USNM 125026. 

3, 4. Plesiotypes (essentially topotypes), from Choctaw Bluff, Warrior River, Ala. USGS 6425, USNM 125025. 

5-17. Plesiotypes—arranged to show gradation in dorsal outline from pointed in figure 5 to squarish in figure 17. 

Figures 5, 13, 4.1 miles north of Creek Stand, Macon County, Ala., USGS 17007, USNM 125027; figures 6, 

8-12, 14-16, from 3.1 miles north of Creek Stand, USGS 17006, USNM 125028; figures 7, 17, one-half mile 

below Broken Arrow Bend, Chattahoochee River, left bank, USGS 5385, USNM 125030. Figures 1-14 are 

left valves; figures 8, 9 are views of left and right valves of same shell; figures 15, 16 are exterior and interior 

views of a right valve; and figure 17 is a view of right valve.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 42

17

OSTREA CRETACEA MORTON
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 43

'OSTREA (LOPHA) AND EXOGYRA
PLATE 43

[All figures natural size

FIGTJBES 1-5. Ostrea (Lopha) ucheensis Stephenson, n. sp. (p. 238).

1, 2. Exterior and interior views of holotype, USGS 17583, USNM 125031. 

3-5. Views of 3 paratypes, USGS 18317, USNM 125033. 

6-10. Exogyra upatoiensis Stephenson (p. 241).

6. Left valve from Catoma Creek, 5 or 6 miles southwest of Montgomery, Ala., USGS 17010, USNM 125020.

7. Left valve from three-fourths mile north by east of Liberty Hill Church, Macon County, Ala., USGS 17576, 

USNM 125019.

8. Left valve from 2J4 miles north-northwest of Warrior Stand, Macon County, Ala., USGS 18306, USNM 125018. 

9, 10. Views of a large shell, from base of Mooreville chalk, Choctaw Bluff, Warrior River, Greene County, Ala., 

USGS 25466, USNM 125021.
PLATE 44

[Figures natural size except as indicated]

FIGURES 1-3. Cymbophora ochilleana Stephenson, n. sp. (p. 244).

1. View, X 1H, of holotype, a right valve. USGS 15501, USNM 125000.

2. View, X 1%, of a paratype, a left valve. USGS 5378, USNM 125004.

3. View, X ll/2, of hinge of a paratype, a right valve. USGS 5374, USNM 125002. 

4-9. Caryocorbula? veatchi Stephenson, n. sp. (p. 245).

4, 5. Right side and dorsal views, X 1& of holotype. USGS 5374, USNM 125036. 

6, 7. Right side and interior views, X 1& of a paratype. USGS 15501, USNM 125038. 

8, 9. Exterior and interior views, X 1& of a paratype, USGS 15501, USNM 125038. 

10-13. Caryocorbula? veatchi longa Stephenson, n. var. (p. 246).

10, 11. Exterior and interior views, X 1& of holotype. USGS 25567, USNM 125041. 

12, 13. Exterior and interior views, X 1H> of a paratype from the same source. USNM 125042. 

14-16. Caryocorbula? georgiana Stephenson, n. sp. (p. 246).

14. View, X 1% of holotype, a right valve. USGS 15501, USNM 125044.

15. Interior view, X 1^4, of a paratype from the same source. USNM 125045.

16. View, X 1& of a rubber cast from internal mold of a left valve. USGS 5378, USNM 125046. 

17-20. Legumen aff. L. carolinense (Conrad), (p. 243).

17-18. Right side and dorsal views of an internal mold. USGS 6408, USNM 125006.

19. Left side of an internal mold (uncoated) to show pallial line and sinus. USGS 5377, USNM 125007.

20. Imprint of exterior of a left valve to show concentric markings. USGS 848, USNM 125008. 

21, 22. Placenticeras benningi Stephenson, n. sp. (p. 247).

21. Lateral view of a young paratype. USGS 5377, USNM 125050.

22. Lateral view of a young paratype. USGS 15501, USNM 125051.
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 44

21

CYMBOPHORA, CARYOCORBULA, LEGUMEN, AND PLACENTICERAS
GEOLOGICAL SURVEY PROFESSIONAL PAPER 274 PLATE 45

COREL LA AND PLACENTICERAS
PLATE 45

[Figures natural size except as indicated]

FIGURES 1-6. Corbula sulcata Lamarck, inserted for comparison with Cretaceous shells (p. 245).

1-3. Views, X 2, of a Recent right valve, a topotype, from the coast of Senegal, West Africa (USNM Ter. Coll.

Moll. 614185).

4-6. Views, X 2, of a left valve, a topotype, from the same collection. 

7—11. Placenticeras benningi Stephenson, n. sp. (p. 247).

7. Side view of the holotype. USGS 5384, USNM 125049.

8, 9. Side and front-edge views of a young paratype; note the slightly excavated ventral band. USGS 15501, 

USNM 125051.

10. View of inner cross section of the paratype shown in plate 44, figure 22, at a diameter of about 65 mm. USGS 

15501, USNM 125051.

11. Front ventral view of the paratype shown in plate 44, figure 21.