<%BANNER%>
Miocene pelecypods of the Choctawhatchee formation of Florida ( FGS: Bulletin 8 )
CITATION SEARCH THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00000442/00001
 Material Information
Title: Miocene pelecypods of the Choctawhatchee formation of Florida ( FGS: Bulletin 8 )
Series Title: ( FGS: Bulletin 8 )
Physical Description: Book
Creator: Mansfield, Wendell C.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management:
The author dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law.
Resource Identifier: ltqf - AAA1618
ltuf - AKM4772
alephbibnum - 002037011
System ID: UF00000442:00001

Full Text








FLORIDA STATE GEOLOGICAL SURVEY
HERMAN GUNTER, State Geologist.








BULLETIN NO. 8








MIOCENE PELECYPODS OF THE
CHOCTAWHATCHEE FORMATION OF FLORIDA

BY
W. C. MANSFIELD
OF THE UNITED STATES GEOLOGICAL SURVEY


* ,


*o .



Published for
The Stale Geological Survey,
Tallahassee, 1932.





6'6~7. 6~f








Published October 8, 1932







Published October 8, 1932








^ e ^ ,









LETTER OF TRANSMITTAL


! To His Excellency, Hon. Doyle E. Carlton,
Governor of Florida.

SSm:
I Somewhat over two years ago Bulletin No. 3 of the Florida Geo-
logical Survey was published. To the average reader this publication
might have seemed highly technical but it was well received by geol-
ogists and workers in paleontology. At that time it was anticipated
another paper would follow which would deal with the pelecypods
of the Choctawhatchee formation and I now have the honor to submit
herewith this second portion to be published as Bulletin No. 8. These
two bulletins form a very complete treatment of the larger inverte-
brate fossils of this formation. Perhaps it may not be out of place
to add that a clear understanding of our geological formations is based
on a knowledge of the remains of animal and plant life which the
rocks contain as well as on the character of the materials composing
the strata. Therefore it is necessary to become familiar with the fos-
sils contained in our various formations in order to the more correctly
interpret their geologic ages and to make correlations with deposits
elsewhere. Thus indirectly do these technical studies result in eco-
nomic utility.
This report entitled "Miocene Pelecypods of the Choctawhatchee
Formation" is by Dr. W. C. Mansfield of the United States Geological
Survey, the author of Bulletin No. 3, and comes as a contribution from
the Federal Survey without expense to the Florida Survey other than
Transportation facilities afforded during the field work and in the
preparation of the illustrations and publication. It is a pleasure to
acknowledge this generous cooperation.
Respectfully,
HERMAN GUNTEB,
Tallahassee, Florida, State Geologist.
June 26, 1932.



Ib







CONTENTS


PACE
INT onDucrT oN ............................................................ 7

BRIE HISTORICAL REVIEW .................................................. 8

DIVISIONS OF THE CHOCTAWHATCHEE FORMATION ............................ 9

THE FAUNAL ZONES ........................................................ 9
Yeodia zone ......................................................... 9
General features ................................................. 9
Character and distribution of fauna ............................... 10
Correlation and age of the fauna.................................. 12
Area zone ...................................................... 12
General features ................................................. 12
Character and distribution of fauna .............................. 12
Correlation and age of the fauna ................................. 13
Ecphora zone ....................................................... 14
General features ................................................. 14
Character and distribution of fauna................................ 15
Correlation and age of the fauna ................................. 16
Cancellaria zone ..................................................... 17
General features ....................................... .... 17
Character and distribution of fauna .............................. 17
Correlation and age of the fauna................................. 18
Summary and brief references ....................................... 19

LIT OF STATIONS ......................................................... 20

- DISTRIBUTION OF SPECIES FROM THE CHOCTAWHATCHEE FORMATION............. 26

SYSTEMATIC DESCRIPTIONS OF SPECIES....................................... 30




ILLUSTRATIONS



PLATEs 1-34. Miocene pelecypods from the Choctawhatchee formation of
Florida ................................................... 165
FIGURE 1. Fossiliferous localities in and adjacent to the Alaqua Creek Val-
ley, Walton County, Fla. ................................... 23
2. Relative sequence of the deposits in the Alaqua Creek Valley,
a section at Red Bay, and columnar section of the Choctaw-
hatchee formation of Florida ............................ 24
3. Map showing fossiliferous localities of the Choctawhatchee for-
mation in western Florida ................................ 25
[5]




I1
A







MIOCENE PELECYPODS OF THE
CHOCTAWHATCHEE FORMATION OF FLORIDA

By WENDELL C. MANSFIELD1

INTRODUCTION
This report is a continuation of a study of the molluscan fauna
of the Miocene Choctawhatchee formation of Florida. In a former
paper2 I described all the then known gastropods and scaphopods of
this formation. After this paper was issued Mr. G. M. Ponton and I
found new fossil beds in the Alaqua Creek Valley. Descriptions of
the pelecypods from these beds are included in this report; the gas-
tropods and scaphopods will be described in a future paper. The
discovery of these fossil beds has not only afforded more substantial
evidence of the close faunal relationship of the Shoal River formation
to the succeeding Choctawhatchee formation but it has established a
more complete sequence of deposits in the Alaqua Creek Valley and
in the area to the east.
The specimens studied for this report were obtained between the
years 1889 and 1932 by several collectors, as is shown by the list of
stations on pages 20-22. Mr. Herman Gunter, State Geologist of Flor-
ida, and his associates obtained at different times many additional
specimens from the borrow pit at Jackson Bluff and along Harveys
Creek, in Leon County. Between the years 1930 and 1932, Mr. G. M.
Ponton and I obtained well-preserved fossils from several new locali-
ties in the Alaqua Creek Valley. Again in 1930 Mr. Ponton visited the
Alaqua Creek Valley and not only procured more fossil material but
determined the altitudes of several of the fossil-bearing beds.
I desire to thank the officials of the United States National Museum
for the use of former collections. Grateful acknowledgment is ex-
tended to Mr. Herman Gunter for his cooperation and for the interest
he has manifested in the preparation of this report by furnishing trans-
portation facilities for my field investigations in 1930 and 1931, and,
with his associates, in preparing the index to this report and assisting
in the proofreading. Thanks are also due to Mr. Gerald M. Ponton,
assistant geologist of the Florida Geological Survey, for valuable
assistance when he accompanied me on my field trips in 1930 and 1931
and was instrumental in obtaining many fine specimens.
1Published with the permission of the Director of the United States Geological
Survey.
2Mansfield, W. C., Miocene gastropods and scaphopods of the Choctawhatchee
formation of Florida: Florida Geol. Survey Bull. 3, 1930.





FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT


I have had the benefit of the advice of Dr. L. W. Stephenson, Dr.
C. W. Cooke, Dr. Julia Gardner, and Dr. W. P. Woodring, of the United
States Geological Survey. Helpful information has been afforded by
the works of the late Dr. William Healey Dall, especially his excellent
memoir entitled "Contributions to the Tertiary fauna of Florida with
especial reference to the Miocene Silex beds of Tampa and the Plio-
cene beds of the Caloosahatchee River," published in the Transactions
of the Wagner Free Institute of Science, of Philadelphia. There has
been before me for reference the excellent paper of Dr. Julia Gardner
entitled "The molluscan fauna of the Alum Bluff group of Florida,"
published as Professional Paper 142-A to 142-E, of the United States
Geological Survey. Miss L. E. Thorwarth painstakingly typed the
manuscript and helped in other ways, and Mr. F. Stearns MacNeil
prepared and assorted many of the specimens for study. The photo-
graphs used for the illustrations were made in the laboratory of the
United States Geological Survey by Mr. W. 0. Hazard, and most of
the prints were retouched by Miss M. K. Sumner, of the same Survey.
The types of the new species are deposited in the United States
National Museum. A set of named pelecypods, including topotypes
so far as practicable, has been deposited with the Florida Geological
Survey.

BRIEF HISTORICAL REVIEW

In 1892 Dall3 referred to the Chesapeake group all the beds in
Florida that were then considered of newer Miocene age. He recog-
nized two subdivisions-the "Jacksonville limestone" in the eastern
part of Florida and the "Ecphora bed" in the western part. He
says:4
At Alum Bluff the group is represented by what I have termed the Ecphora
bed. of gray marl, with over 100 species of fossils, many of which are common to
North Carolina, Virginia, and Maryland. It has a thickness here of 30 feet or more.
Later Dall5 applied the name aluminouss clay" to a 25-foot bed
of grayish clay overlying the "Ecphora bed."
In 1909 Matson and Clapp6 included both the "Ecphora bed" and
the aluminouss clay" of Dall in their Choctawhatchee formation,
named from Choctawhatchee River, with the type locality in the
vicinity of Red Bay, a small settlement about 18 miles southeast of
DeFuniak Springs, Walton County, Fla.
3Dall, W. H., and Harris, G. D., correlation papers; Neocene: U. S. Geol.
Survey Bull. 84, pp. 123, 124, 1892.
4Idem, p. 124.
5Dall, W. H., and Stanley-Brown, Joseph, Cenozoic geology along the Apalachi.
cola River: Geol. Soc. America Bull., vol. 5, pp. 168, 169, 1894.
6Matson, G. C., and Clapp, F. G., Florida Geol. Survey Second Ann. Rept., pp.
108, 114, 1909.





CHOCTAWHATCHEE PELECYPODS


In 1914 Olsson7 described two new species of pelecypods and one
species of gastropod from the upper fossiliferous bed at Alum Bluff,
Fla.; in 1916 he described one new gastropod species from the same
locality.
In 1916 Is described the outcrop at Red Bay, listed the fauna, and
described and illustrated the following new forms: Area (Scapharca)
staminea rubisiniana, Leda choctawhatcheensis, Phacoides (Pleurolu-
cina choctawhatcheensis, Astarte (Ashtarotha) vaughani, and Diplo-
donta waltonensis. I said:9
On account of the small collections and the unidentifiable character of some
specimens it is not possible to determine the exact synchronism of the fauna with
that of the upper bed at Alum Bluff; however, the species present indicate that the
beds represent nearly the same if not precisely the same horizon.
In 1929 Cooke and Mossom'O gave a rather full description of the
Choctawhatchee formation. On the basis of my study of the fauna,
they divide the formation in ascending order into three faunal zones-
the Arca zone, the Ecphora zone, and the Cancellaria zone.
The following year I" described all the then known gastropods
and scaphopods from the formation, and gave more fully the faunal
characteristics of the different zones.
In 1930 Cushman12 described all the known Foraminifera of the
Choctawhatchee formation.
DIVISIONS OF THE CHOCTAWHATCHEE FORMATION
The fossiliferous beds of the Choctawhatchee formation are now
separated into four faunal zones, in ascending order as follows: Yoldia
waltonensis zone, referred to in this paper as the Yoldia zone; Arca
rubisiniana zone, referred to as the Area zone; Ecphora quadricostata
umbilicata zone, referred to as the Ecphora zone; and the Cancellaria
propevenusta zone, referred to as the Cancellaria zone.
THE FAUNAL ZONES
YOLDIA ZONE
General features.-The name Yoldia zone was proposed by Ponton
and myself'i for a bed carrying many individuals of the genus Yoldia.
7Olsson, Axel, New and interesting Neocene fossils from the Atlantic Coastal
Plain: Bull. Am. Paleontology, vol. 5, pp. 43-72, 1914; New Miocene fossils; Idem,
pp. 123-152, 1916.
SMansfield, W. C., Mollusks from the type locality of the Choctawhatchee marl:
U. S. Nat. Mus. Proc., vol. 51, pp. 599-607, 1916.
9Idem, p. 603.
toCooke, C. W.. and Mossom, Stuart, Geology of Florida: Florida Geol. Survey
Twentieth Ann. Rept., pp. 37-227 (see especially pp. 138-149), 1929.
"Mansfield, W. C., Miocene gastropods and scaphopods of the Choctawhatchee
formation of Florida: Florida Geol. Survey Bull. 3, 1930.
12Cushman, J. A., The Foraminifera of the Choctawhatchee formation of Flor-
ida: Florida Geol. Survey Bull. 4, 1930.
1sMansfield, W. C., and Ponton, G. M., Faunal zones in the Miocene Choctaw-
hatchee formation of Florida: Washington Acad. Sci. Jour., vol. 22, p. 86, 1932.





10 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The type locality is on the Frazier farm (formerly the Spencer farm),
Walton County, in the SE.14 sec. 18, T. 2 N., R. 19 W.
The sediments composing the zone consist of dark-gray to bluish
micaceous clayey sand with inclusions of carbonaceous particles. The
thickness has not been accurately determined, but it probably does
not exceed 20 feet.
The zone is believed to represent the basal bed of the Choctaw-
hatchee formation. Its contact with the underlying Shoal River for-
mation is not revealed at the type locality, but at the Chester Spence
farm, in the NE.1/4 sec. 17, T. 2 N., R. 19 W., a locality about 11/ miles
northeast of the Frazier farm, which was revisited by G. M. Ponton
and by the writer in 1932, its contact with the Shoal River formation
is strongly indicated in the low bluff. The face of the bluff at the
Chester Spence farm is marked by a horizontal oxidized line about
5 feet above the base of the exposure. The molluscan faunas below
and above this line have different faunal elements. The two beds
probably are conformable, and the introduction of the new faunal
element that persisted through the following Area zone may have
been caused by a shift in the off-shore currents.
The pelecypod fauna at the Chester Spence farm, United States
Geological Survey station 10612, was placed by Gardner14 in the Shoal
River formation, but Ponton and myself15 placed it in the Shoal River
formation provisionally, though stating that it appears to be transi-
tional from that of the Shoal River formation to that of the Choctaw-
hatchee formation. In this paper the fauna in the lower part of the
bluff at the Chester Spence farm is assigned to the Shoal River for-
mation, whereas the fauna of the upper part of the bluff is provision-
ally assigned to the Yoldia zone of the Choctawhatchee formation.
The zone is separated from the overlying Area zone because of its
content of many large shells of Yoldia, a genus which generally indi-
cates that the temperature of the water in which it lived was rather
cold.
Character and distribution of fauna.-Because the shells at the
type locality of the Yoldia zone are very fragile, only a few species
have been collected. The following species of pelecypods from this
locality have been determined: Yoldia waltonensis n. sp., Arca rubi-
siniana Mansfield, Phacoides crenulatus (Conrad), and Cardium sp.
The following species of pelecypods were collected by Ponton
and the writer in 1932 directly above an oxidized line, which is about
5 feet above the base of the bluff, and 2 or 3 feet higher up, or from
14Gardner, Julia, The molluscan fauna of the Alum Bluff group of Florida:
U. S. Geol. Survey Prof. Paper 142-A to 142.E, 1926-1928.
15Mansfield, W. C., and Ponton, G. M., Faunal zones in the Miocene Choctaw-
hatchee formation: Washington Acad. Sci. Jour., vol. 22, p. 85, 1932.





CHOCTAWHATCHEE PELECYPODS


the upper part of the bluff at the Chester Spence farm (U. S. Geological
Survey station 12718). An asterisk indicates the occurrence of the
same species in the bed below the oxidized line or in the lower part
of the same bluff (U. S. Geological Survey station 12717): Nucula
proxima Say, Yoldia waltonensis Mansfield (a somewhat smaller shell
than that at the Frazier farm), *Arca (Anadara) strebla Gardner,
Arca (Anadara) rubisiniana Mansfield var.?, Ostrea haitensis Sower-
by?, *Periploma discus Gardner, Crassatellites meridionalis rubisin-
iana Mansfield, *Cardium n. sp.?, *Cardium waltonianum Dall,
*Chione defuniak Gardner var. The following species of pelecypods
were collected from the lower bed (station 12717) but not from the
upper bed: Nucula defuniak Gardner, Pecten sp. cf. P. choctaw-
hatcheensis Mansfield, Crassatellites densus Dall, and Callocardia pro-
sayana Gardner.
In the list of species from the upper bed are five that also occur
in the lower bed. Of the others, Yoldia waltonensis occurs in the
Yoldia zone at the type locality but has not been found in the Shoal
River formation, and Crassatellites meridionalis rubisiniana is one of
the characteristic species in the following Area zone, replacing C.
Sdensus Dall, of the Shoal River formation.
Although considerable care was exercised in collecting the fossils,
there is a bare possibility that some of the species listed from the
upper bed really belong with the lower bed, as the oxidized line on
the surface is less distinct in entering the bluff, but this possibility
can not be confirmed with the fossils at hand.
The fauna from the lower bed at the Chester Spence farm is more
closely allied to but probably a little younger than that occurring
.either at United States Geological Survey station 5618, 3/2 miles
southwest of DeFuniak Springs (probably the old Langley farm), or
at station 9959, Pleasant Ridge Church, both of which places are only
a short distance north of the locality on the Chester Spence farm.
The fauna at station 5618 carries many shells of Cardium and has
been referred by Gardners1 to the upper zone of the Shoal River
formation. The location given by Gardner17 for station 3747 is incor-
rect (an error of the clerk in copying the station record). Instead of
being 8 miles south of DeFuniak Springs it is 8 miles nearly due west
of that place, in the SW.1/4 sec. 34, T. 3 N., R. 20 W. According to
Mr. G. M. Ponton, the fossils from United States Geological Survey
station 3747 were taken from a well on the Parker place at a depth
of 30 feet.
16Gardner, Julia, The molluscan fauna of the Alum Bluff group of Florida:
U. S. Geol. Survey Prof. Paper 142-E, p. 235, 1928.
17Idem, p. 111.





12 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The nature of the fauna of the Yoldia zone indicates that it lived
in rather cold and shallow water.
Correlation and age of the fauna.-The fauna from this zone is so
meager and so poorly preserved, especially that from the type locality,
that it is difficult to correlate it with an outside fauna; on stratigraphic
evidence it is placed in the upper part of the middle Miocene.
ARCA ZONE
General features.-The name Area zone was proposed by me's in
1929. The zone is typically exposed at Red Bay, Walton County,
where it is about 21 feet thick and forms the lowermost fossiliferous
bed in the exposure. A nearly unfossiliferous upper bed of clay at
this locality, which was formerly included in the Area zone, is now
placed in the Ecphora zone.
The zone consists mainly of very fossiliferous gray sandy marl
having an estimated total thickness of about 55 feet.
The Area zone probably rests conformably upon the Yoldia zone.
The upper limit of the Area zone is provisionally placed at the contact
of the marl with an overlying plastic clay bed which in the section at
Red Bay carries no determinable fossils. The shells in the marl are
worn and broken. The absence of fossils from the clay and the litho-
logic difference between the marl and the clay suggest an unconform-
ity between the two beds, but this relationship has not been fully
established.
The fauna of the Area zone is represented in Walton County at
Red Bay, Bell farm (U. S. Geological Survey stations 12044 and 12045),
Vaughan Creek (U. S. Geological Survey stations 12046 and 12047),
and Alice Creek (U. S. Geological Survey station 12527). In Bay
County the zone is represented in the highest fossiliferous bed along
Taylor Branch, on Mr. Bryant Scott's farm (U. S. G. S. station 12267).
Character and distribution of fauna.-The zone carries many well-
preserved fossils, which occur more abundantly in thin lenses. About
60 different kinds of pelecypods have been recognized, of which 45
species and subspecies have been named. The genera whose species
are represented by many individuals are Leda, Area, Periploma,
Thracia, Crassatellites, Phacoides, Diplodonta, Asaphis, and Panope.
The character of the fauna indicates that it lived in cooler water
than that of the Shoal River fauna, and in slightly warmer water than
that of the succeeding fauna of the Ecphora zone.
Some of the species that appear to be confined or nearly so to the
lsMansfield, W. C, in Cooke, C. W., and Mossom, Stuart, Geology of Florida:
Florida Geol. Survey Twentieth Ann. Rept, p. 140,1929. Mansfield, W. C., Miocene
gastropods and scaphopods of the Choctawhatchee formation of Florida; Florida
Geol. Survey Bull. 3, p. 15, 1930.





CHOCTAWHATCHEE PELECYPODS 13

Arca zone are Leda choctawhatcheensis Mansfield, Arca (Anadara)
rubisiniana Mansfield, Pecten macdonaldi Oleson, Chlamys (Lyropec-
* ten) pontoni n. sp., Crenella duplinensis waltoniana n. subsp., Crassa-
tellites (Crassatellites) meridionalis rubisiniana n. subsp. (occurs also
in the Yoldia zone), Phacoides (Pleurolucina) choctawhatcheensis
SMansfield, Diplodonta waltonensis Mansfield, Callocardia rubisiniana
n. sp.
The species in the Arca zone that also occur in the Shoal River
formation are Leda polychoa defuniak Gardner, Periploma discus
Gardner, Cardita defuniak Gardner, Divaricella waltoniana Gardner,
Alveinus micculus Gardner, Corbula funiakensis Gardner, Glycymeris
pectinata (Gmelin), Echinochama arcinella (Linnaeus), Diplodonta
acclinis (Conrad). Most of these species occur in the highest part of
the Shoal River formation and are represented by very few individuals
in the Area zone.
Some of the Shoal River species that were not found in the Arca
zone are "Diluvarca" hypomela (Dall), "Diluvarca" strebla Gardner,
"Diluvarca" waltonia Gardner, Chlamys (Plagioctenium) nicholsi
Gardner, Astarte (Bythiamena) isosceles Gardner, Crassatellites
(Scambula) densus Dall, Cardium (Trachycardium) plectopleura
Gardner, Dosinia dalli Gardner, Clementia sp., Spisula (Hemimactra)
valhosierr Gardner.
Correlation and age of the fauna.-The fauna of the Area zone is
closely related to that of the Shoal River formation, from
which its species were mainly descended. It is more closely related
to the fauna of the upper part of the Shoal River formation than to
that of the lower part. However, the introduction of many new forms,
some of which occur in the succeeding Ecphora zone, indicates that
it is younger than the Shoal River fauna. Out of 45 species and sub-
species named, 9 occur in the Shoal River formation, 13 in the Ecphora
zone, and 6 (or 13+ per cent) occur in the Recent fauna.
The discovery by Mr. Ponton and me of beds in the Alaqua Creek
Valley that carry well-preserved fossils (U. S. Geological Survey
stations 12044, 12045, 12046, 12047) has added 22 identified species
to the Area zone that have not been found at Red Bay, the type locality
of the Area zone. Doubtless this increase is due in part to the eroded
and broken condition of the specimens found at Red Bay.
The Alaqua Creek fauna (U. S. Geological Survey stations 12044-
12047) is placed in the Arca zone because it contains a number of
species, some of which are represented by many individuals, which
have not been found in the Shoal River fauna but which occur at Red
Bay. Some of these species are Leda choctawhatcheensis Mansfield,
Area rubisiniana Mansfield, Pecten macdonaldi Olsson, Chlamys





14 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

pontoni n. sp., Crenella duplinensis waltoniana n. subsp., Crassatellites
meridionalis rubisiniana n. subsp., Diplodonta (Sphaerella) subvexa
(Conrad), Panope goldfussii (Wagner). The beds exposed at the
Bell farm (stations 12044, 12045) and along Vaughan Creek (stations
12046, 12047) are believed, however, to carry the earliest fauna of
the Area zone, whereas the lower fossiliferous bed at Red Bay carries
the latest fauna of the Arca zone.
Some of the species, including Chlamys (Lyropecten) pontoni,
Thracia conradi, and Panope goldfussii, probably migrated south-
ward from the Miocene sea of the Chesapeake Bay region, in which
the Chesapeake group was deposited.
In the following table are indicated five West Indian and Central
American Miocene species that appear to be identical with or closely
related to five species in the Arca zone.
Species of the Area zone Identical or closely related species from
the West Indies and Central America
Pecten (Pecten) macdonaldi Olsson..... Pecten (Pecten) macdonaldi Olsson,
from Toro limestone, Panama
Chlamys (Plagioctenium) choctawhatche- Chlamys levicostatus Toula, Gatun for-
ensis, n. sp .......................... nation, Panama
Phacoides (Pleurolucina) choctawhatche- Phacoides (Pleurolucina) quadricos-
ensis Mansfield .................... tatus Dall, Bowden marl, Jamaica
Protocardia (Lophocardium) gurabica Protocardia gurabica Maury, Gurabo
vaughaniana, n. subsp. .............. formation, Dominican Republic
Dosinia (Dosinidia) acetabulum blount- Dosinia delicatissima Brown and Pils.
ana, n. subsp. ...................... bry, Gatun formation, Panama
The Pecten that I have identified as P. macdonaldi may prove to
be more closely related to P. gatunensis Toula, a species in the Gatun
formation of the Canal Zone, than to P. macdonaldi.
Outside of Florida the fauna of the Arca zone appears to be most
closely related to that of the Gatun formation of Panama, though with
what part or zone of that formation has not been determined. The
fauna of the St. Marys formation of Maryland and Virginia appears
to have lived at about the same time as that of the Arca zone.
The age of the fauna of the Area zone is therefore believed to be
late middle Miocene.
ECPHORA ZONE
General features.-The "Ecphora bed," named by Dall and Har-
ris,19 is now known as the Ecphora zone.20 Its type locality is at Alum
Bluff, on the Apalachicola River, Liberty County, Fla., where it forms
19Dall, W. H, and Harris, G. D., Correlation papers; Neocene: U. S. Geol Sur-
vey Bull. 84, pp. 123, 124, 1892.
20Mansfield, W. C., in Cooke, C. W., and Mossom, Stuart, Geology of Florida:
Florida Geol. Survey Twentieth Ann. Rept., p. 140, 1929.





CHOCTAWHATCHEE PELECYPODS 15

the uppermost fossiliferous bed of the section. The sediments com-
:posing the zone consist of a sandy clay that is bluish where nn-
weathered. The bed ranges in thickness from 15 to 25 feet at different
places along the bluff at its type locality.
SAt Alum Bluff the Ecphora zone, with somewhat doubtful uncon-
formable relations, rests upon a fossil leaf-bearing sand that Cooke
and Mossom21 questionably refer to the Alum Bluff group. At Jack-
son Bluff the same authors22 refer to the Hawthorn formation a bed
of clay resembling fuller's earth, which underlies the Ecphora zone.
At Red Bay a bed of poorly fossiliferous plastic clay, which overlies
the Area zone, is believed to represent the Ecphora zone.
At Alum Bluff the Ecphora zone is conformably overlain by the
aluminouss clay" of Dall and at Jackson Bluff by the Cancellaria zone.
The aluminouss clay" bed has not been recognized in the section at
Jackson Bluff or in any section along the Ochlockonee River. If this
clay bed is older than the beds referred to the CanceUaria zone, as it
appears to be, then there was a short hiatus in time between the two
beds at Jackson Bluff. If, however, there was no interruption to
[ sedimentation, the aluminouss clay" at Alum Bluff must have been
r deposited approximately at the same time as the beds referred to the
Cancellaria zone at Jackson Bluff and elsewhere. Wherever the Can-
V cellaria zone has been recognized it contains an abundance of fossils.
SOnly casts of mollusks have been observed in the aluminouss clay,"
and these are very rare, except in its lower part. Whether the physical
conditions, which apparently prevented the existence of abundant
living forms, or the chemical constituents of the sediments, which dis-
solved the shells, were of only local extent in the Alum Bluff area,
has not been fully determined.
The zone is represented at the localities indicated below under
United States Geological Survey station numbers:
SLeon County: Lower upper Miocene bed at abandoned mill on Harveys Creek,
about half a mile above highway bridge on road to Bloxham (station 1/965); basal
upper Miocene bed at Jackson Bluff, Ochlockonee River (station 3423).
S Liberty County: Alum Bluff, upper fossiliferous bed (station 2210); cut in old
road to Watsons Landing, about 2 miles north of Alum Bluff (station 1/962).
Calhoun County: Near Clarksville (station 8862); Darlings Slide, Chipola
River (station 1/672); Abes Spring, Chipola River (station 1/959); 5 miles below
Baileys Ferry, Chipola River (station 3418).
Washington County: Near Red Head Still, Choctawhatchee River (station
1/951).
Walton County: Near Permenter's old place, Alaqua Creek (station 12048);
Red Bay, upper poorly fossiliferous plastic clay bed, about 27 feet thick.
Character and distribution of fauna.-This report records 82
species and subspecies of pelecypods from the Ecphora zone; of these
l2Cooke, C. W., and Mossom, Stuart, Geology of Florida: Florida GeoL Survey
Twentieth Ann. Rept., p. 108, 1929.
221dem, p. 124.





16 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

39 occur in the upper fossiliferous bed at Alum Bluff. Dall lists2
45 species from the upper fossiliferous.bed at Alum Bluff and ad-
jacent outcrops.
The following are some of the species that appear to be confined
to this zone: Area idonea alumensis n. subsp., Area aresta Dall, Pecten
leonensis n. sp., Chlamys jefersonius Say, Astarte floridana Dall, Cras-
satellites meridionalis Dall, Phacoides contracts (Say), Cardium vir-
ginianum Conrad, Dosinia acetabulum obliqua Dall, and Mulinia
congesta (Conrad), a heavy form. This zone is especially character-
ized by many individuals of large and heavy forms of the species
Mulinia congesta.
The fauna of the Ecphora zone, as pointed out by Dr. Dall, evi-
dently lived in cold water.
A meager fauna from Alexander Spring, Lake County (U. S. Geo-
logical Survey station 11142), tentatively referred to the top of the
Hawthorn formation by Cooke and Mossom,24 probably belongs to
the Ecphora zone; the aspect of the fauna indicates that it is not
srratigraphically lower than this zone. A fauna similar to that at
Alexander Spring was dredged from Tampa Bay at St. Petersburg; a
list of the species, which were identified by me, is given by Cooke
and Mossom25 and referred by them to the Choctawhatchee formation.
In South Carolina a fauna very similar to that in the Ecphora zone
occurs at Raysors Bridge, Edisto River, Colleton County. The com-
mon species noted are Leda trochilia trochilia Dall, Yoldia tarpaeia
Dall, and Chlamys jeffersonius Say.
Still farther north, in Virginia and North Carolina, a number of
the same species occur in the early part of the Yorktown formation,
among which are Cardium virginianum Conrad and Chione cribraria
Rogers.
Correlation and age of the fauna.-On the basis of the persistence
of the fossil species to the Recent fauna of the Atlantic and Gulf
coasts, the following enumeration has been compiled: Pelecypods,
16 per cent; gastropods and scaphopods, 13 per cent; combined pelecy-
pods, gastropods, and scaphopods, 14 per cent. This enumeration is
the same as that given by Dall26 for the so-called Chesapeake, by which
he obviously meant the Miocene of Florida.27 Dall's list includes some

23Dall, W. H, Contributions to the Tertiary fauna of Florida: Wagner Free
Inst. Sci Trans, voL 3, pt. 6, pp. 1596-1598, 1903.
24Cooke, C. W.. and Mossom, Stuart, Geology of Florida: Florida GeoL Survey
Twentieth Ann. Rept., pp. 131-132, 1929.
2Idem, p. 148.
26Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1617 (table), p.
1618 (explanation), 1903.
27Idem, pp. 1596-1598.





CHOCTAWHATCHEE PELECYPODS 17

species from localities in Walton County, Coes Mill in Liberty County,
and elsewhere, that I have not included in the Ecphora zone.
S The Ecphora zone is correlated with the lower part of the York-
'town formation of the Chesapeake group of Virginia and the Caro-
linas, or that part of the Yorktown formation stratigraphically below
the fragmental beds as exposed at Yorktown, Va.

" CANCELLARIA ZONE

General features.-The name Cancellaria zone was proposed by
Mansfield28 to include beds that carry the latest Miocene fauna. This
zone is typically exposed in the highest fossiliferous beds along Har-
Sveys Creek, in the SW.1/4 sec. 9, T. 1 S., R. 3 W., Leon County, Fla.
The zone is composed of fine to coarse-grained clayey sand, replete
with fossils, and has an estimated total thickness of 25 to 30 feet.
The stratigraphic relations of the Cancellaria zone to the under-
K lying Ecphora zone at Jackson Bluff have already been discussed on
page 15. On the Econfina River, about 1 mile below the highway
bridge in Bay County (U. S. Geological Survey station 1/953), the
Cancellaria zone rests upon an indurated cavernous rock of lower
Miocene (Chipola) age. Wherever the upper limit of the zone has
Been observed it is overlain by unfossiliferous sands or gravels of
Pliocene age.
The zone has been recognized at the localities described below
under United States Geological Survey station numbers:
Leon County: Harveys Creek, about half a mile above the abandoned mill
(station 3421); highest fossiliferous bed at abandoned mill on Harveys Creek
(station 1/961); Double Branch (station 1/966); highest fossiliferous bed at
SJackson Bluff, Ochlockonee River (stations 3422 and 11732).
Liberty County: At 2 miles north of Hosford and 2%4 miles northwest of Hos-
ford (stations 3671, 3672) ; on Mr. S. D. Johnson's place near Woods (station 1/961).
Bay County: On the Econfina River, about 1 mile below highway bridge, in
sec. 4, T. 1 S, R. 13 W. (station 1/953).
Washington County: The "Deadens," about 5 miles southeast of Greenhead
(station 8176); Hamlin Pond, southeast of Greenhead (station 1/422), and Gully
Pond, southeast of Greenhead (station 1/706).
Franklin County: Rock Creek, half a mile south of Knox Still Landing
(station 7474).

Character and distribution of fauna.-About 120 pelecypod forms
have been recognized in the Cancellaria zone, of which 103 species
and subspecies are named. The following are some of the species that
are apparently confined to this zone in Florida: Barbatia (Cunearca)
propatula Conrad, Area (Anadara) idonea harveyensis n. subsp., Arca
S(Anadara) improcera Conrad, Chlamys (Plagioctenium) eboreus dar-
28Mansfield, W. C., in Cooke, C. W., and Mossom, Stuart, Geology of Florida:
Florida Geol. Survey Twentieth Ann. Rept., p. 140, 1929.





18 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

lingtonensis Dall, Chlamys (Plagioctenium) comparilis Tuomey and
Holmes, Placunanomia plicata Tuomey and Holmes, Codakia (Jago-
nia) magnoliana Dall, Chione (Chione) procancellata n. sp., Chione
(Timoclea) grus (Holmes), Macoma (Psammacoma) hosfordensis n.
sp., Mulinia congesta (Conrad), thin form.
The following species of the Cancellaria zone have not been re-
ported from the Duplin marl of the Carolinas but occur in the Plio-
cene Caloosahatchee marl of Florida: Pleurodon woodii Dall, Crassi.
nella acuta (Dall), Lucina chrysostoma (Meuschen), Diplodonta ca-
loosaensis Dall, Parastarte triquetra (Conrad), Tellina (Eurytellina)
alternate Say, Tagelus (Mesopleura) divisus (Spengler), Panope flori.
dana Heilprin.
The fauna of the Cancellaria zone evidently lived in rather warm
water.
Correlation and age of the fauna.-Out of 103 named species and
subspecies of pelecypods from the Cancellaria zone, 56 (54.3 per cent)
occur in the Duplin marl of the Carolinas and 23 (22- per cent) have
survived in the Recent fauna of the coast. Out of 137 species and
subspecies of gastropods and scaphopods named in a previous paper,
48 (35 per cent) occur in the Duplin marl and 23 (17 per cent) have
survived in the Recent fauna. By combining the above results it is
seen that 43.3 per cent of the molluscan fauna occurs in the Duplin
marl and 19 per cent survives in the Recent fauna.
Dall29 reports 20 per cent and Gardner30 27 per cent of the Duplin
fauna that has survived in the Recent fauna.
About 39 per cent of the species and subspecies of pelecypods of
the Cancellaria zone occur in the Pliocene Caloosahatchee marl.
Dall31 reports about 28+ per cent of the molluscan fauna of the
Duplin marl in the Pliocene Caloosahatchee marl.
As'noted above, a few species of pelecypods from the Can.
cellaria zone have not previously been reported in beds older than
Pliocene, but this does not warrant placing the Cancellaria zone in
the Pliocene, for the fauna as a whole is more closely allied to that
of the upper Miocene than to that of the Pliocene. A larger propor-
tion of the pelecypod fauna from the zone occurs in the Miocene
Duplin marl than in the Pliocene Caloosahatchee marl. The propor-
tion of gastropods and scaphopods that so occur has not been deter-.
mined. However, the fauna of the Cancellaria zone indicates that the
uppermost Miocene is closely related to the Pliocene and that the
time interval between the accumulation of the deposits was not long.
29Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1617, 1903.
sOGardner, Julia, cited by Vaughan, T. W., Am. Assoc. Petroleum Geologists,
Bull. vol. 7, p. 521, 1923.
3lIdem.





CHOCTAWHATCHEE PELECYPODS


A fauna similar to that of the Cancellaria zone was found at Kis.
ee, Osceola County, in a well between the depths of 65 and
00 feet, and about 3 miles south of Kissimmee in a well at a depth
150 feet.
iThe Cancellaria zone is correlated with the Duplin marl of the
linas, as its fauna appears to have lived at approximately the
e time.

SUMMARY AND BRIEF REFERENCES
The results obtained in the study of the pelecypod fauna of the
octawhatchee formation closely agree with the results obtained
Sthe study of the gastropod and scaphopod faunas as published in
Bulletin 3 of the Florida Geological Survey. In that paper I did not
definitely state the age of the Area zone, but in the present paper I
have assigned that zone to the upper part of the middle Miocene and
have correlated it with some part of the Gatun formation of Panama
and with the St. Marys formation of the Chesapeake group. One new
faunal zone-the Yoldia zone-is recognized in this paper.
The percentages of Recent species present in the different zones,
as previously given in this paper, are as follows:
Zones Percentages Recent fauna
cn'tceUaria zone ....... Pelecypods ................. 22 Combined, 19
S(Gastropods and scaphopods.. 17.~
pora one ............ Pelecypods ............... 16 t Combined, 14
Gastropods and scaphopods.. 13
Area zone, pelecypods only........................... ..13+
odia zone,2
I have determined the percentages of Recent species and sub-
es of foraminifera in the different faunal zones of the Choctaw-
hatchee formation, as recorded in the table and text of the paper by
ushman,83 with the following results:
Percentages of
Zones Recent species
CA ceUaria zone .............................................. 79+
.phora zone ............................................... 78+
rcea zone (Red Bay locality only).......................... 63
Area zone (station 1/682) .................................... 50

SDr. Cushman kindly assisted me in checking the Recent occur-
nce of some of the species and subspecies. The results show, as
th the mollusks, that the percentage of Recent species increases
upward in the column in accordance with the successive later ages
the faunas.

82No estimate as the fauna is too meager.
83Cushman, J. A., The Foraminifera of the Choctawhatchee formation: Florida
eoL Survey Bull. No. 4, 1930.





20 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The locality on Bryant Scott's farm (U. S. Geological Survey
station 1/682) is in sec. 22, T. 2 N., R. 12 W., Bay County. The Foram.
inifera collected at this locality probably came from the highest
fossiliferous bed in the section. The mollusks collected by Mr. Ponton
and me on Taylor Branch (U. S. Geological Survey station 12267)
came from the highest fossiliferous bed and are assigned to the Area
zone. The Foraminifera probably came from the same bed as the
mollusks. Dr. Cushman34 calls attention to the difference in the
Foraminifera found in Bay County at U. S. Geological Survey stations
1/682 and 1/593. Station 1/593 is about 12 miles southwest of station
1/682. The fauna at station 1/682 is considered older than that at
station 1/593.
Cushman and Ponton35 have described one new species of Foram-
inifera, Virginulina miocenica, which they record as occurring in
Florida at the type localities of the Oak Grove sand and Shoal River
formation, and at Vaughan Creek. They referred the Vaughan Creek
locality questionably to the Choctawhatchee formation. The Foram-
inifera from Vaughan Creek evidently came from station 12046 of
the present paper. I have referred the fauna at this locality to the
Choctawhatchee formation.

LIST OF STATIONS

LEON COUNTY
3421 (T. W. Vaughan, 1900); 1/946 (W. C. Mansfield, 1925); Florida Geological
Survey, 1925 and later. Harveys Creek, about half a mile above abandoned mill,
SW.1/ sec. 9, T. 1 S., R. 3 W. (Cancellaria zone.)
3422 (T. W. Vaughan, 1900); 1/963 (W. C. Mansfield, 1925). Jackson Bluff,
left bank of Ochlockonee River (SW.1/4 sec. 16, T. 1 S., R. 4 W.) Highest fossilifer.
ous upper Miocene bed. (Cancellaria zone.)
11732. Borrow pit, about 600 feet from the wagon bridge over river at Jack.
son Bluff. Fossils from upper part of the marl and directly beneath the unfossili.
ferous surface material. Collected by Florida Geological Survey, 1927. (Cancel.
laria zone.)
3423 (T. W. Vaughan, 1900); 1/967 (W. C. Mansfield, 1925). Just above wagon
bridge at Jackson Bluff, left bank of Ochlockonee River. Lower upper Miocene
bed. (Ecphora zone.)
4993. One mile west of Holland post office. Fossils taken from well, 28 feet
deep. G. C. Matson, collector, 1908. (Mainly Ecphora zone.)
1/964. Highest bed at abandoned mill on Harveys Creek, about half a mile
above the highway bridge on road to Bloxham (Sec. 8, T. 1 S., R. 3 W.) W. C.
Mansfield, collector, 1925. (Cancellaria zone.)
1/965. Lower upper Miocene bed at abandoned mill on Harveys Creek, about
half a mile above highway bridge on road to Bloxham. W. C. Mansfield, collector,
1925. (Ecphora zone.)
1/966. Double Branch, just above highway bridge on road to Bloxham (see.
8, T. 1 S., R. 3 W.). W. C. Mansfield, collector, 1925. (Cancellaria zone.)
34Idem, pp. 5, 6.
35Cushman, J. A., and Ponton, G. M., A new Virginulina from the Miocene of
Florida: Contr. Cushman Laboratory for Foraminiferal Research, vol. 7, pt. 2, pp.
32, 33, pl. 4, figs. 14-16, 1931.






CHOCTAWHATCHEE PELECYPODS 21

LIBERTY COUNTY
2210 (Frank Burns, 1889);; 2569 (W. H. Dall and J. S. Brown, 1893); 3417
W. Vaughan, 1900) ; 7081 (C. W. Cooke and W. C. Mansfield, 1914); 1/670
Gardner, 1923); 1/956 (W. C. Mansfield, 1925); 1/1056 (C. W. Cooke and
S. Mossom, 1926). Upper fossiliferous bed at Alum Bluff, left bank of Apa.
ola River. (Ecphora zone, typical.)
3671. (T. W. Vaughan, 1902); 1/958 (W. C. Mansfield, 1925). Hosford's mill
early Coe's mill) on Big Creek, about 2 miles north of Hosford. (Cancellaria
3672. Robinson's old mill on Robinson's Mill Creek, about three-fourths mile
rth.norwest of Hosford's mill (formerly Coe's mill) and about 23 miles north-
rthwest of Hosford. T. W. Vaughan, collector, 1902. (Cancellaria-zone.)
1/961. On S. D. Johnson's place, near Woods (sec. 26, T. 1 S., R. 8 W.), about
miles below Bristol. W. C. Mansfield, collector, 1925. (Cancellaria zone.)
1/962. Cut on old road to Watsons Landing, about 2 miles north of Alum
and about the same distance from Apalachicola River (sec. 1, T. 1 N., R.
W.). Base of bed about 40 feet above the river terrace. W. C. Mansfield,
lector, 1925. (Ecphora zone.)
CALHOUN COUNTY
3418. Bailey post office, about 5 miles below Baileys Ferry. Fossils taken
SwelL T. W. Vaughan, collector, 1900. (Ecphora zone.)
1/959. Abes Spring, east side of Chipola River, about 3% miles southeast of
ksville (sec. 17, T. 1 S., R. 9 W.). W. C. Mansfield, collector, 1925. (Ecphora
sone.)
8862. From high cliff half a mile northeast of Clarksville. F. G. Clapp, col.
lector, 1920. (Ecphora zone.)
1 954. From lowest fossiliferous bed exposed on Fourmile Creek, about half
t mile northwest of Clarksville. W. C. Mansfield, collector, 1925. G. M. Ponton,
1930. (Ecphora zone.)
1/672 (Julia Gardner, 1923); 1/960 (W. C. Mansfield, 1925). Darlings Slide,
st side of Chipola River, about 21 miles southeast of Clarksville. (Ecphora
lone.)
BAY COUNTY
1/953. On Econfina River about 1 mile below highway bridge over river,
s. 4, T. 1 S.. R. 13 W. Fossils about 8 feet above river level and directly above
an indurated and porous limestone. W. C. Mansfield, collector, 1925. (Cancel-
lra one.)
12267. Taylor Branch, a stream flowing into Econfina Creek, on Bryant Scott's
farm, sec. 22, T. 2 N., R. 12 W. Highest fossiliferous bed in this area. W. C.
field and G. M. Ponton, collectors, 1931. (Area zone.)

WASHINGTON COUNTY
8176. The "Deadens," about 5 miles southeast of Greenhead. E. H. Sellards,
llector, 1918. (Cancellaria zone.)
1/422. Hamlin Pond; southeast of Greenhead, in sec. 7(?), T. 1 N., R. 13 W.
C. W. Cooke and Julia Gardner, collectors, 1921. (Cancellaria zone.)
. 1/706 (C. W. Cooke and Julia Gardner, 1921); 1/955 (W. C. Mansfield, 1925).
Gully Pond, southeast of Greenhead, in sec. 14(?), T. 1 N., R. 14 W. (Cancellaria
sone.)
1/951. Uppermost fossiliferous bed overlying the lower Miocene bed near
Rocky Landing, on Choctawhatchee River, and about 1 mile from Red Head Still.
. C. Mansfield, collector, 1925. (Upper part of Ecphora zone or lower part of
Cmenellaria zone.)
WALTON COUNTY
4975 (G. C. Matson, 1908) ; 1/671 (Julia Gardner, 1923); 1/947,1/948 and 1/949
W. C. Mansfield, 1925). Bluffs about 1 mile east and southeast of Red Bay. (Area

7152 (C. W. Cooke, 1914); 1/673 (Julia Gardner, 1923); 1/950 (W. C. Mans.
,1925). E. Gomillion's field, a quarter of a mile east of Red Bay. (Arca zone.)






22 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

12044. At head of small branch flowing into Sconier's Mill Creek, on the
rear of the G. H. Bell farm (formerly the G. R. Spencer farm), 7.1 miles south.
southwest of DeFuniak Springs, on Steel Church road (NE.I sec. 29, T. 2 N., R
19 W.). W. C. Mansfield and G. M. Ponton, collectors, 1930. (Arca zone.)
12045. At head of small branch flowing into Sconier's Mill Creek on the
G. H. Bell farm, about one-fourth mile south of station 12044 (about center of
sec. 29, T. 2 N., R. 19 W.). W. C. Mansfield and G. M. Ponton, collectors, 1930.
(Area zone.)
12046. Vaughan Creek (locally called Blounts Creek), about 3 miles from
its entrance into Alaqua Creek and about 61/ miles nearly suuth of DeFuniak
Springs( sec. 27, T. 2 N. R. 19 W.). Fossils obtained a short distance below the head
of a shallow gorge which cuts through the marl. (Old farm of Mrs. F. H. Davis.)
Elevation of shell bed, 93 feet above sea level. W. C. Mansfield and G. M. Ponton,
collectors, 1930-31. (Arca zone.)
12047. Vaughan Creek (locally called Blounts Creek). Fossils obtained from
a few yards below an old mill to half a mile below it and about 1% to 2 miles
from the creek's entrance into Alaqua Creek, in sec. 28, T. 2 N., R. 19 W. (J. W.
Fahrenholtz's old farm.) Elevation of shell bed at water's level at lower end of
creek, 76 feet. W. C. Mansfield and G. M. Ponton, collectors, 1930. (Arca zone.)
12718. Chester Spence farm (NE.1/ sec. 17, T. 2 N., R. 19 W.). Fossils col.
elected directly above a horizontal oxidized line, which is about 5 feet above the
base of the bluff, and 2 or 3 feet higher up. W. C. Mansfield and G. M. Ponton,
collectors, 1932. (Yoldia zone, provisionally.)
12048. In an old roadcut in east bank of Alaqua Creek on P. Permenter's
old place, about 10 miles nearly south of DeFuniak Springs, in sec. 17, T. 1 N., R.
19 W. Shells collected at an altitude of 53 feet above sea level W. C. Mansfield
and G. M. Ponton, collectors, 1930. (Ecphora zone.)
12527. Bluff on Alice Creek, in the SE.% sec. 8, T. 1 N., R. 19 W. Shell bed
about 15 feet above water's level of the creek. G. M. Ponton, collector, 1930.
(Area zone, upper part.)
12060. Frazier's old farm (formerly Spencer farm), one-fourth mile south.
east of center of sec. 18, T. 2 N., R. 19 W. Fossils obtained at a dripping spring
which heads a small branch flowing into Alaqua Creek. W. C. Mansfield and
G. M. Ponton, collectors, 1930-31. (Yoldia zone.)

FRANKLIN COUNTY

7474. Rock Creek, half a mile south of Knox Still Landing, New River, and
about 5 miles northwest of Carrabelle. E. H. Sellards, collector, 1915. (Cancel-
laria zone.)


U. S. Geological Survey station numbers as shown on Figure 1:
3742. Shell Bluff, type locality of the Shoal River formation.
3747. Parker place, Shoal River formation.
4975, 7152. Vicinity of Red Bay, Choctawhatchee formation. Upper part of
the Area zone and overlying Ecphora zone.
5618. Langley's old farm, Shoal River formation, Cardium zone.
9959. Pleasant Ridge Church or Alaqua, Shoal River formation, Cardium zone.
10612. Chester Spence's farm (early collection). Later collection by Mans-
field and Ponton from lower part of bluff (12717), Shoal River formation, and from
upper part of bluff (12718), Yoldia zone provisionally.
12044. Bell farm, upper locality, Choctawhatchee formation, Area zone.
12045. Bell farm, lower locality, Choctawhatchee formation, Arca zone.
12046. Vaughan Creek, upper locality, Choctawhatchee formation, Area zone.
12047. Vaughan Creek, lower locality, Choctawhatchee formation, Area zone.
12048. Permenter's old place, Choctawhatchee formation, Ecphora zone.
12060. Frazier's old farm, Choctawhatchee formation, Yoldia zone.
12527. Alice Creek, Choctawhatchee formation, upper part of the Arca zone.





































FIGURE l.-Fossiliferous localities in and adjacent to the Alaqua Creek Valley, Walton County, Fla.
















oE 1 ~i
e e "o
**5 (fl .1)
L I.

r a ii





n Ini n


I f


a S
in <
J 0

I
U')


Upper
Miocene


Upper-
S nliddle
- Miocene

Middle
Miocene


4 5 6 7 8 Miles


Aluinu cMy

rEphora zone

Area zone

Yoldia zone
Cardium zone
and older


FIcURE 2.-Relative sequence of the deposits in the Alaqua Creek Valley, a section at Red Bay, and columnar section of the Choc-
tawhatchee formation of Florida in its relation to the underlying Shoal River formation. 1, At stations 9959 and 5618, indi.
cates the top of the shell bed. 2, At station 9959, indicates the top of the bed with shell impressions.


160'-
I d-
1200
I od
80'
Wl-

O'-
0


B'Tig ...Blg --^B^.. "=- -." ---

S52

Sea level


.,,,,,,,,,,,


wr


-'-----











4Y





-U- ~ "la









UH ig on
--


a-~





Scale




StAndrom l





FICURE 3.-Map showing fossiliferous localities of the Choctawhatchee formation in western Florida.





26 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Figure 2 shows the relative sequence of the deposits in the Alaqua
Creek Valley, Walton County, from Pleasant Ridge Church to Per-
menter's old place; a section at Red Bay, a place east of the Alaqua
Creek Valley; and a generalized columnar section of the Choctaw-
hatchee formation of Florida in its relation to the Shoal River for-
mation.
The altitudes of the beds in the Alaqua Creek Valley were mainly
determined by Mr. G. M. Ponton, and the altitude of the top of the
Miocene beds about 1 mile east of Red Bay is adapted from the level
run to this place by Herman Gunter.36 "Sea level" does not apply to
the generalized columnar section.
The map presented in Figure 3 shows the positions, as indicated by
United States Geological Survey station numbers, of the fossiliferous
localities of the Choctawhatchee formation in western Florida.

DISTRIBUTION OF SPECIES FROM THE CHOCTAWHATCHEE
FORMATION
Those marked C are from the Cancellaria zone; E from the
Ecphora zone; A from the Area zone, and Y from the Yoldia zone. S
denotes the occurrence of the species in the Shoal River formation;
D in the Duplin marl of the Carolinas, and R the persistence of the
species in the Recent fauna of the Coast.

PELECYPODA
Nucula taphria Dall, C, E, D.
proxima Say, C, E, A, Y, D, R.
Leda choctawhatcheensis Mansfield, A.
cho-tawhatcheensis vaughanensis Mansfield, n. subsp., A.
trochilia trochilia Dall, E.
trochilia coensis Mansfield, n. subsp, C, D.
trochilia hamlinensis Mansfield, n. subsp.?, C, D.
polychoa defuniak Gardner, A, S.
Yoldia (Adrana) kurzi Mansfield, n. sp, C.
tarpaeia Dall, E
waltonensis Mansfield, n. sp, Y. A?.
Plenrodon woodii Dali, C.
gunteri Mansfield, n. sp., A.
Trinacria meekii Dall?, A.
Glycymeris pectinata (Gmelin), C, E, A, D, S, R.
americana (DeFrance). C, E, D, R.
subovata (Say), E, D, S.
Area (Area) occidentalis Philippi, C, S, R.
Barbatia (Plagiarca) candida floridana Mansfield, n. subsp., C.
(Calloarca) leonensis Mansfield, n. sp., C, D.
(Granoarca) propatula Conrad, C, D.
(Granoarca) propatula busana Harris, C.
Area (Fossularca) adamsi (Shuttleworth Ms.) Dall, C, D, R.
(Noetia) incile Say, C, E, D.
(Anadara) idonea alumensis Mansfield, n. subsp, E.
86Sellards, E. H, and Gunter, Herman, Geology between the Choctawhatchee
and Apalachicola Rivers in Florida: Florida Geol. Survey Tenth and Eleventh
Ann. Repts., p. 94, 1918.






CHOCTAWHATCHEE PELECYPODS


Anadara) idonea harveyensis Mansfield, n. subsp., C.
(Anadara) rubisiniana Mansfield, A, Y.
(Anadara) sellardsi Mansfield, n. sp., C.
(Anadara) callicestosa (Dall), C, E, D.
(Anadara) lienosa Say, C, E, D.
(Anadara) improcera Conrad, C, D.
(Anadara) aresta Dall, E.
(Anadara) propearesta Mansfield, n. sp., C, A?
(Anadara) camps Dall, C, E.
(Cunearca) scalaris Conrad, C, E, D.
ina n. sp.?, C, D.
teria multangula (H. C. Lea) ?, E.
streaka disparilis Conrad, C, E, D.
baitensis Sowerby?, A, Y.
,eculpturata Conrad, C, E, D.
'ecten (Pecten) ochlockoneensis Mansfield, n. sp., C, E.
t(Peeten) macdonaldi Olsson, A.
r(Pecten) leonensis Mansfield, n. sp., E.
3lamys (Lyropecten) pontoni Mansfield, n. sp., A.
L.(Lyropecten) jeffersonius Say, E.
(Plagioctenium) eboreus eboreus Conrad, E.
(Plagioetenium) eboreus darlingtonensis Dall, C, D.
(Plagioctenium) comparilis Tuomey and Holmes, C, D.
(Plagioctenium) comparilis jacksonensis Mansfield, n. subsp., E.
(Plagioctenium) choctawhatcheensis Mansfield, n. sp., A.
(Plagioctenium) choctawhatcheensis redbayensis Mansfield, n. subsp., A.
Lmusium mortoni Ravenel, C, E, D.
'Ieudamussium species, A.
licatula marginata Say, C, E, D.
ima (Mantellum) carolinensis Dall, C, D.
Lnomia simplex D'Orbigny, C, E, A?, D, R.
Iacunanomia plicata Tuomey and Holmes, C, E?, D.
plicata floridana Mansfield, n. subsp., E.
lytilus conradianus D'Orbigny?, C, D?
'renella duplinensis waltoniana Mansfield, n. subsp., A.
'eriploma discus Gardner, A, Y, S.
Ihracia conradi Couthony, E. A, R.
andora (Clidiophora) crassidens Conrad, E.
(Kennerleyia) arenosa Conrad, C, E, A, D.
(Kennerleyia) species, aff. arenosa Conrad, C.
uaspidaria (Cardiomya) ornatissima (D'Orbigny) Dall, C, R.
S(Cardiomya) ornatissima vaughani Mansfield, n. subsp., C.
LStarte (Ashtarotha) floridana Dall, E.
, (Ashtarotha) floridana leonensis Mansfield, n. subsp., C.
S(Ashtarotha) vaughani Mansfield, E?, A.
[(Ashtarotha) glenni jacksonensis Mansfield, n. subsp., E.
species aff. A. symmetrica Conrad, E.
rassatellites (Crassatellites) meridionalis Dall, E.
(Crassatellites) meridionalis rubisiniana Mansfield, n. subsp., A, Y.
S(Crassatellites) meridionalis alicensis Mansfield, n. subsp., A.
(Crassatellites) gibbesii (Tuomey and Holmes) Dall, C, E, D, R.
(Crassatellites) alaquaensis Mansfield, n. sp., E.
rassinella lunulata (Conrad), C, E, D.
acuta (Dall), C.
dupliniana Dall, C. D.
waltoniana Mansfield, n. sp., A.
ardita (Carditamera) vaughani Dall, E.
(Carditamera) arata (Conrad), C, E?, D.
(Carditamera) arata harveyensis Mansfield, n. subsp., C, A.
(Carditamera) defuniak Gardner, A, S.
enericardia (Cyclocardia) granulata Say, C, E, D.
(Pleuromeris) perplana var. abbreviata (Conrad), C, E, D.
(Pleuromeris) tridentata decemcostata Conrad, C, E, D.
(Pleuromeris) scituloides Olsson, C?, E.





28 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Chama congregate Conrad, C, E, D, R.
striata Emmons, C, D.
Echinochama arcinella (Linnaeus), C, E, A, D?, S, R.
Codakia (Jagonia) magnoliana Dall, C, D.
(Jagonia) speciosa (Rogers) ?, C, E.
(Jagonia) leonensis Mansfield, n. sp, E.
Lucina chrysostoma (Meuschen) Philippi, C, A?, R.
Phacoides (Pseudomiltha) anodonta (Say), A, D.
(Pleurolucina) choctawhatcheensis Mansfield, A.
(Cardiolucina) trisulcatus multistriatus (Conrad), C, D.
(Lucinisca) cribrarius (Say), C, E, D.
(Lucinoma) contracts (Say), E, D?.
(Parvilucina) crenulatus (Conrad), C E, A, D.
(Parvilucina) crenulatus pemphigus Dall, E.
(Parvilucina) multilineatus (Tuomey and Holmes), C, A, D, R.
(Bellucina) tuomeyi Dall, C, E, D.
Divaricella quadrisulcata (D'Orbigny), E, D, R.
waltonia Gardner, A, S.
Diplodonta acclinis (Conrad), C, D, S.
caloosaensis Dall, C.
ochlockoneensis Mansfield, n. sp., E.
waltonensis Mansfield, A, S.
(Sphaerella) subvexa (Conrad), E, A.
Sportella constricta (Conrad), C, D.
protexta (Conrad), C, D, R.
Hindsiella carolinensis coensis Mansfield, n. subsp., C, D?.
Alveinus micculus Gardner, A, S.
Aligena aequata (Conrad), E, D.
Cardium (Trachycardium) stiriatum leonense Mansfield, n. subsp., C.
(Trachycardium) oedolium harveyense Mansfield, n. subsp., C, D?.
(Cerastoderma) virginianum Conrad, E.
(Cerastoderma) laqueatum blountense Mansfield, n. subsp., A.
(Cerastoderma) acutilaqueatum Conrad?, C, E.
(Cerastoderma) sp. cf. taphrium Dall, A.
(Trigoniocardia) deadenense Mansfield. n. sp., C, A?.
(Laevicardium) serratum Linnaeus, C, E, R.
Protocardia jacksonense Mansfield, n. sp., E.
(Lophocardium) gurabica vaughaniana Mansfield, n. subsp., A.
Dosinia (Dosinidia) acetabulum (Conrad), C, E.
(Dosinidia) acetabulum obliqua Dall, E.
(Dosinidia) acetabulum blountana Mansfield, n. subsp., E, A.
(Dosinidia) elegans (Conrad)?, C, D?.
Transennella carolinensis Dall, C, D.
caloosana Dall?. C.
Gafrarium (Gouldia) metastriatum (Conrad), C, E, D.
Macrocallista (Paradione) reposta (Conrad), n. subsp.?, C.
(Paradione) maculata (Linnaeus) ?, A.
(Paradione) waltonensis vaughanensis Mansfield, n. subsp., A.
Callocardia (Agriopoma) sayana Conrad?, C, E, A.
(Agriopoma) rubisiniana Mansfield, n. sp., A.
Pitaria (Hyphantosoma) waltonensis Gardner?, A.
Cylichnella sp. cf. C. tennis (Ricluz), C.
Chione (Chione) procancellata Mansfield, n. sp., C.
Chione (Chione) erosa Dall, C, E.
(Chione) cortinaria (Rogers), E.
(Lirophora) xesta Dali, E.
(Lirophora) ulocyma Dall, C, E.
(Lirophora) ulocyma deadenensis Mansfield, n. subsp., C.
(Lirophora) ulocyma propeulocyma Mansfield, n. subsp., C.
(Lirophora) ulocyma leonensis Mansfield, n. subsp., C.
(Lirophora) ulocyma sconierensis Mansfield, n. subsp., C?, E?, A.
(Lirophora) latilirata athlete Conrad, C, E, D, R.
Chione (Timoclea) grus (Holmes), C, D, R.





CHOCTAWHATCHEE PELECYPODS


en campechiensis ochlockoneensis Mansfie'd, n. subsp., C.
eampechiensis carolinensis (Conrad), C, D?.
campechiensis alaquaensis Mansfield, n. subsp, E.
tridacnoides rileyi Conrad, E.
tridacnoides rileyi Conrad?, A.
emma magna Dall, E, D.
ovata Mansfield, n. sp., C.
arastarte triquetra (Conrad), C, R.
ellina (Eurytellina) alternate Say, C, R.
(Merisca) aequistriata Say, C, E, A, D, R.
(Moerella) macilenta Dall, C, D.
(Moerella) sayi deadenensis Mansfield, n. subsp, C, A.
gilla eutykta Gardner and Aldrich, C, D.
[etis magnoliana Dall. C, D.
coma alumensis Dall, E.
virginiana coensis Mansfield, n. subsp., C, E?.
gardnerae Mansfield, n. sp., E.
.(Peammacoma?) holmesii Dall?, E.
S(Psammacoma) hosfordensis Mansfield, n. sp., C.
ele alumensis Dall, E.
alumensis leonensis Mansfield, n. subsp, E.
coensis Mansfield, n. sp., C.
carinata (Conrad)?, C, E
bellastriata (Conrad) ?, E.
purpurascens (Gmelin). E, R.
proficua harveyensis Mansfield, n. subsp., C.
(Semelina) nuculoides (Conrad), C, D. R.
(Semelina) clappi Mansfield, n. sp., C, E.
ra subreflexa jacksonensis Mansfield, n. subsp., E.
aequalis (Say) ?, C.
Aphis centenaria (Conrad), C, A, D.
Tagelus (Mesopleura) divisus (Spengler), C, R.
Donax fossor Say, C, D, R.
Ensis directs (Conrad), E, A?, D. R.
Mactra (Mactrotoma) undula Dall?, C.
Spisnla (Hemimactra) delumbis (Conrad), C, A.
Sp. a, ?aff. S. confraga (Conrad), E.
p. b, aff. S. subparilis (Conrad), C, A.
Mulinia congesta (Conrad), heavier form, E.
congesta (Conrad). lighter form, C, A, D.
FErilia lata Dall, C, D.
Corbula (Corbula) waltonensis rubisiniana Mansfield, n. subsp., C, E, A.
(Caryocorbula) nucleata Dall, E. A.
S(Caryocorbula) nucleata deadenensis Mansfield, n. subsp., C, E.
,Corbula (Caryocorbula) inaequalis Say, E, A, Y, D.
.(Caryocorbula) barrattiana leonensis Mansfield, n. subsp., C, E, D.
. (Caryocorbula) sp. aff. C. cuneata Say, E.
S(Caryocorbula) funiakensis Gardner, A. S.
Panope reflexa (Say), C, D.
floridana (Heilprin), C, R.
Sgoldfussii (Wagner), E, A.
.Gastrochaena ligna H. C. Lea?, C, D.






30 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

SYSTEMATIC DESCRIPTIONS OF SPECIES
Phylum MOLLUSCA
Class PELECYPODA
Order PRIONDESMACEA
Superfamily NUCULACEA
Family NUCULIDAE
Genus NUCULA Lamarck, 1799
Nucula taphria Dall
Plate 1, Figures 1, 2.
1898. Nucula taphria Dall, Wagner Free Inst. Sci. Trans., voL 3, pt. 4, p. 576,
pl. 32, fig. 14.
1919. Nucula lapteria Dall (typographic error for taphria). Gardner and Aldrich,
Acad. Nat. Sci Philadelphia Proc, vol. 71, p. 18.
(In list with species from locality near Mayesville, S. C.)
The figured type of Nucula taphria Dall came from the Duplin
marl at the Natural Well, N. C. This species is well characterized
by its small size, solid texture, cuneiform shape, and strong, grooved
concentric sculpture.
Specimens from the St. Marys formation, Maryland, referred to.
Nucula taphria Dall by Glenn,37 have much larger and more quadrate
shells than specimens from the Duplin marl, and may be a subspecies
of Nucula taphria.
Occurrence: Upper Miocene: Ecphora zone-station 8862, half a
mile northeast of Clarksville, Calhoun County (2 valves); station
1/962, cut in road to Watsons Landing, Liberty County (1 valve);
station 3423, lower upper Miocene bed at Jackson Bluff, Leon County
(4 valves). Cancellaria zone-station 1/964, Harveys Creek, highest
bed at abandoned mill (1 valve).
Outside occurrence: Upper Miocene: Duplin marl of the Carolinas.

Nucula proxima Say
Plate 1, Figures 3, 4, 5.
1820. Nucula obliqua Say, Am. Jour. Sci, 1st ser., vol. 2, p. 40. Not Lamarck, 1819.
1822. Nucula proxima Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 2, p. 270.
1856. Nucula proxima Say. Tuomey and Holmes, Pleiocene fossils of South Caro.
lina, p. 53, pl. 17, figs. 7-9.
1858. Nucula proxima Say. Emmons, North Carolina Geol. Survey Rept., p. 287,
fig. 208-B.
1889. Nucula proxima Say. Dall, U. S. Nat. Mus. Bull. 37, p. 42, pl. 56, fig. 4.
1898. Nucula proxima Say. Dall, Wagner Free Inst, Sci. Trans., vol. 3, pt. 4, p. 574.
1919. Nucula proxima Say. Gardner and Aldrich, Acad. Nat. Sci. Philadelphia
Proc., vol. 71, p. 18.
Dall38 gave the varietal name trunculus to the living northern
specimens, which, he states: "are almost smoothly truncated behind,
the escutcheon is not impressed to any marked degree, and there is no
angle at the margin below the escutcheon."

37Glenn, L. C., Maryland Geol. Survey, Miocene, p. 400, pl. 108, figs. 9, 11, 1904.
88Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 574, 1898.





CHOCTAWHATCHEE PELECYPODS


The living form from the southern coast Dall considered more
pical of Nucula proxima as described by Say. Dall9 states:
r.The fossils, so far as yet observed, are all more like the variety trunculus,
responding to the cooler temperature of the sea in this region during Miocene
mes, while the Pliocene specimens are rather undersized, which may have been
mt result of the increasing temperature which characterized that epoch in Florida.
iThe majority of the specimens studied for this paper resemble
tore nearly the living specimens of Nucula proxima ranging from
forth Carolina to Charlotte Harbor, Fla., than they do the more
northern living specimens. The specimens occurring in the highest
pds of the Miocene compare in size with those in the Pliocene of
lorida.
.Occurrence: Upper middle Miocene: Yoldia zone provisionally,
Stion 12718, upper bed at Chester Spence farm, Walton County.
ica zone-station 12046, Vaughan Creek, Walton County, upper
cality (common); station 12044, Bell place, Walton County, upper
mcality (rare). Upper Miocene: Ecphora zone-station 8862, half a
dile northeast of Clarksville, Calhoun County (rare); station 3423,
ier upper Miocene bed at Jackson Bluff, Leon County (common).
'ascellaria zone-station 3671, 2 miles north of Hosford, Liberty
punty (common); station 3672, 23/4 miles northwest of Hosford
abundant); station 3421, Harveys Creek, half a mile above the
abandoned mill, Leon County (common); station 1/966, Double
ranch above highway bridge, Leon County (rare); station 11732,
orrow pit near Jackson Bluff, Leon County (common); station 3422,
highest bed at Jackson Bluff (common); station 1/961, near Woods,
liberty County (rare); station 1/422, Hamlin Pond, Washington
unty (common); station 1/955, Gully Pond, Washington County
common); station 1/953, 1 mile below Econfina bridge, Bay County
common .
ktOutside occurrence: As reported the range of this species extends
1om the lower part of the Chesapeake Miocene to the Recent.

Family LEDIDAE
Genus LEDA Schumacher, 1817
I Leda choctawhatcheensis Mansfield
Plate 1, Figures 8, 11.
16. Leda choctawhatcheensis Mansfield, U. S. Nat. Mus. Proc., vol. 51, p. 604, pl.
i- 113, figs. 2, 4.
IThis species is characterized by its small size, rather flat shell,
orng concentric ribs over the middle of the disk, and its distinct
mule.
): Occurrence: Upper middle Miocene: Arca zone-Walton County,
la., near Red Bay; station 12046, Vaughan Creek, upper locality
S89Idem, p. 574.





32 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

(abundant); station 12044, Bell farm, upper locality (abundant);
station 12045, Bell farm, lower locality (rare).
This species is related to Leda trochilia coensis, a new subspecies
from old Coe's Mill, Hosford, Liberty County, Fla.

Leda choctawhatcheensis vaughanensis Mansfield, n. subsp.
Plate 1, Figures 14, 17.
The shell of the new subspecies agrees in outline and convexity
with the shell of Leda choctawhatcheensis. The main difference
consists in the nature of the concentric sculpture. The concentric
sculpture over the middle of the disk of L. choctawhatcheensis con-
sists of strong, widely spaced ribs, whereas the concentric sculpture
on the new subspecies consists of weaker, more closely and more uni-
formly spaced ribs..
Cotypes (Cat. No. 371610, U. S. N. M.) measure: Larger specimen
(right valve) : Length, 6.5 mm.; height, 4.6 mm. Smaller specimen
(left valve) : Length, 4.6 mm.; height, 2.7 mm.
Type locality: Station 12046, Vaughan Creek, about 3 miles from
its entrance into Alaqua Creek and about 61/2 miles nearly south of
DeFuniak Springs, Walton County.
Occurrence: Upper middle Miocene: Arca zone, known only from
its type locality (rare).
Leda trochilia trochilia Dall
Plate 1, Figures 12, 15.
1898. Leda trochilia Dall, Wagner Free Inst. SeL Trans., vol. 3, pt. 4, p. 590, pL 32,
figs. 4, 12.
This species is characterized by its nearly equilateral shell, which
is sculptured by rather uniformly, usually continuous, narrow, con-
centric riblets. The riblets usually extend from the middle of the
disk to the anterior end and are rarely intercalated by other lines.
The carina is weakly crenulated by the continuation of the concentric
riblets, a feature which is more marked on young and well-preserved
specimens.
Occurrence: Upper Miocene: Ecphora zone-Alum Bluff, upper
bed, Liberty County, type locality (common); station 1/962, cut in
old road to Watsons Landing, Liberty County (rare); station 8862,
half a mile northeast of Clarksville, Calhoun- County (common).;
station 3423, lower upper Miocene bed at Jackson Bluff, Leon County
(rare); station 1/672, Darlings Slide, Chipola River, Calhoun County
(rare).
Outside occurrence: Upper Miocene: Station 5295, Raysors Bridge,
Colleton County, S. C. The shell from this locality is more strongly
sculptured than typical specimens, but in shape it agrees closely with
the typical form.





CHOCTAWHATCHEE PELECYPODS


Leda trochilia coensis Mansfield, n. subsp.
Plate 1, Figures 7, 10.
re new subspecies differs from Leda trochilia trochilia Dall in
Wring a more elongate and a narrower shell and in the nature of the
Ilpture. The sculpture consists of rather strong, sharp concen-
ribs over the middle of the shell, continuous but finer over the
erior end and obsolete in the depressed area in front of the pos-
0ior carina. A riblet intercalates the persistent riblets on the
erior end. The ribs on the ventral area are weaker and usually
tend posteriorly to the carina. The beaks are low and are orna-
~ented with fine concentric riblets. Lunule not distinctly indicated.
ceutcheon marked with longitudinal striae. Carina weakly crenu-
ed.. Some specimens, but not the specimen selected for the holo-
have fine radials between the concentric sculpture.
Holotype with attached valves (Cat. No. 371110, U. S. N. M.)
assures: Height, 4.2 millimeters; length, 8 millimeters; diameter,
millimeters.
Occurrence: Upper Miocene: Cancellaria zone-station 3672, 23
ties northwest of Hosford, Liberty County, type locality (abun-
ant); station 3671, 2 miles north of Hosford (abundant); station
1706, Gully Pond, Washington County (abundant); station 1/422,
[Imlin Pond, Washington County (abundant); station 1/961, near
Toods, Liberty County (rare); station 1/953, 1 mile below Econfina
ridge, Bay County (abundant); station 3422, upper bed at Jackson
luff, Ochlockonee River, Leon County; station 11732, borrow pit
War Jackson Bluff (abundant); station 1/966, Double Branch, just
0ove bridge, Leon County (rare?); station 1/964, abandoned mill,
arveys Creek, Leon County, highest bed; station 3421, Harveys
eek, half a mile above abandoned mill, Leon County (abundant).
Outside occurrence: Upper Miocene: Duplin marl, Mayesville,

Leda trochilia hamlinensis Mansfield, n. subsp.?
[? = L. trochilia coensis n. subsp.]
Plate 1, Figures 6, 9
This subspecies differs from Leda trochilia trochilia Dall in having
more elongate and a narrower shell and finer sculpture, and from
Strochilia coensis in having finer sculpture. It is more closely
elated to the latter than to the former and may represent a mutation
f subspecies coensis. The sculpture consists of rather closely set and
Father uniformly placed, moderately narrow, concentric riblets, the
iblets being weakly imbricated on the anterior side. Lunule not well
eined. Escutcheon marked with longitudinal striae. Carina very
aintly crenulated.

I..





34 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Cotypes (Cat. No. 371111, U. S. N. M.) measure: Right valve:
Height, 5.5 mm.; length, 11 mm.; diameter, 2.3 mm. Left valve of
another specimen: Height, 5.5 mm.; length, 10 mm.; diameter,
2.5 mm.
This subspecies is less regularly sculptured than is Leda acuta
(Conrad).
Occurrence: Upper Miocene: Cancellaria zone-station 1/422,
Hamlin Pond, Washington County, type locality (common); station
1/706, Gully Pond, Washington County (common); station 1/966,
Double Branch, above highway bridge, Leon County (common);
station 1/953, 1 mile below Econfina bridge, Bay County (common);
station 3421, Harveys Creek, half mile above abandoned mill, Leon
County (common); station 11732, borrow pit near Jackson Bluff,
Leon County (common); station 3422, highest bed at Jackson Bluff
(rare?).
Outside.occurrence: Upper Miocene: Near Mayesville, S. C.
I have included in this subspecies a form which, instead of having
strong concentric sculpture, is nearly smooth.

Leda polychoa defuniak Gardner
Plate 1, Figures 13, 16
1926. Leda polychoa defuniak Gardner, U. S. Geol. Survey Prof. Paper 142-A, p. 18,
pL 3, figs. 11-12.
The type locality of this subspecies is station 5618, 31/2 miles
southwest of DeFuniak Springs, Walton County, Fla.
Doctor Gardner writes, in part:40
The subspecies characterized by the feeble or obsolete sculpture upon the
rostrum and usually by a less sharp and regular sculpture upon the disk, is the
common Leda in the environs of DeFuniak Springs. The sculpture as a rule is
sharper and more regular on specimens from the type locality of the subspecies
than it is on the individuals that occur along Shoal River at the type locality of
Leda polychoa in a strict sense. The range of variation in outline is lower than
in the restricted species, and the short, highly inflated type is absent. The char-
acters of the subspecies are commonly more marked in the young than in the
adult, for in some of the adults the sculpture toward the ventral margin persists
across the rostrum.

Occurrence: Upper middle Miocene: Arca zone-station 12046,
Vaughan Creek, upper locality, Walton County (10 valves); station
12047, Vaughan Creek, lower locality (1 fragment); station 12044,
Bell farm, upper locality (4 valves); station 12267, Bryant Scott's
farm,'Bay County (2 fragments and identification uncertain).
Other occurrence: Middle Miocene: Shoal River formation at a
number of localities in Walton County, Fla. (Gardner). Questionably
occurs in the Oak Grove sand (Gardner).
40Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-A, pp. 18-19, 1926.





CHOCTAWHATCHEE PELECYPODS


Genus YOLDIA Miller, 1842
Yoldia tarpaeia Dall
Plate 1, Figures 18, 19, 20, 23
Yoldicrarpaeia Dall, Wagner Free Inst. ScL Trans., vol. 3, pt. 4, p. 597.
Dall gave the following description of this species:
Shell small, smooth, ovoid, moderately convex, rather solid for its size, with
ends rounded, the posterior smaller, the base evenly arcuated; lunule very
; escutcheon smooth, or marked only by lines of growth, with a single
ellose elevated line very close to the shell margin, which in young or worn
imens is often obscured; beaks low, hinge-line nearly straight, pallial sinus
ed deep, nearly reaching the vertical of the beaks; about twenty anterior and
een posterior small, narrow teeth, separated by a subumbonal chondrophore.
n, of a large specimen, 14.25; a perfect but smaller one measures, Ion. 9.5, alt. 5,
3 mm.
The type of this species which came from the upper bed at Alum
luff, Liberty County, Fla., apparently has not been figured.
,This species is closely related to Yoldia laevis (Say), but it has
rportionately shorter anterior end and is less slender.
Cotypes, Cat. No. 114852 (U. S. N. M.).
Occurrence: Upper Miocene: Ecphora zone-upper bed at Alum
Aluff (quite rare); station 1/960, Darlings Slide, Chipola River, Cal-
houn County (quite rare); station 7258, Abes Spring, Chipola River,
Ihoun County (rare); station 8862, half mile northeast of Clarks-
Calhoun County (rare).
Outside occurrence: Upper Miocene: Station 5295, Raysor Bridge,
eton County, S. C.
Yoldia waltonensis Mansfield, n. sp.
W Plate 1, Figures 21, 22
Shell fragile, very large, elongate, and moderately inflated. Pos-
ior region longer, more tapering, and more pointed and compressed
an the anterior region. Beak situated in front of middle of hinge
'n, and 3 mm. from anterior end. Lunule wide and marked only
th growth lines. Escutcheon narrower and less well defined than
nule. Sculptured on the umbonal area and disk only with incre-
Lental growth lines.
. Holotype (Cat. No. 371611, U. S. N. M.) measures: Length, 31 mm.;
eight, 13 mm.
Type locality: Station 12060, Frazier farm (SE.1/4 sec. 18, T. 2 N.,
19 W.), Walton County.
Some valves represent much larger shells than the holotype, the
get being 40 mm. in length.
Yoldia soror Gardner, a Shoal River species, has a much smaller
with a less pointed posterior extremity than the new species.
Yoldia tarpaeia Dall, a species apparently confined to the Ecphora
has a smaller and relatively higher shell.
Yoldia laevis Say, especially the form that has been referred to





36 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

this species and collected from the Yorktown formation of Virginia,
is closely allied to the new species but has a relatively higher shell.
Occurrence: Upper middle Miocene: Yoldia zone-type locality
(common); station 12718, upper bed at Chester Spence farm, Wal-
ton County. Arca zone-Alice Creek, Walton County (internal cast;
identification uncertain). The specimens at station 12718 are a little
smaller than those at the type locality and probably occupy a position
at the base of the Yoldia zone.
Subgenus ADRANA H. and A. Adams
Yoldia (Adrana) kurzi Mansfield, n. sp.
Plate 2, Figures 5, 8
Shell rather thin, elongate, and weakly convex. Beaks depressed
and inconspicuous with a small prodissoconch and situated 12 mm.
from the anterior end. Anterior region shorter, a little wider, and
less narrowly rounded marginally than posterior region. Escutcheon
long, narrow, bounded by a low, raised, finely crenulated line and
marked longitudinally with fine lines. Lunule shorter than escutch.
eon and less well defined. Exterior of shell without posterior carina.
A shallow depression extends from the beak to the ventral margin
on the anterior side of the disk. Sculpture composed of imbricated
lamellae, finer over the umbonal area but coarser over the anterior
side and middle of the disk. The dorsal half of the posterior region
is marked only by weak incremental lines. Resilium pit small and
triangular.
Holotype (Cat. No. 371773, U. S. N. M.) measures: Length, 27.5
mm.; height, 8.8 mm.; diameter (both valves), 4.4 mm.
Type locality: Uppermost Miocene bed at Jackson Bluff, Leon
County, Fla.
The holotype is a complete specimen received from the Florida
Geological Survey and collected by Dr. Herman Kurz, Professor of
Botany at the Florida State College for Women, Tallahassee, Florida,
and for whom it is named.
Yoldia perprotracta Dall, a species from the Pleistocene at Mount
Hope, Panama Canal Zone, is related to Yoldia kurzi n. sp., but it has
a narrower shell and the disk is marked by finer concentric sculpture.
Olsson41 described three species: "Leda quitanensis," "Leda ensi-
noides," and "Leda dalliana." These are referred to the subgenus
Adrana. All of these species, according to the illustrations, have nar-
rower and more pointed posterior extremities than Yoldia kurzi n. sp.
Occurrence: Upper Miocene: Cancellaria zone-known only from
the type locality.
41Olsson, A. A., The Miocene of northern Costa Rica: Bull. Am. Paleontology,
vol. 9, pp. 346.348, 1922.





CHOCTAWHATCHEE PELECYPODS 37

Subfamily MALLETIINAE.
Genus PLEURODON S. Wood, 1840
Pleurodon woodii Dall
Plate 2, Figures 1, 3
Pleurodon woodii Dall, Wagner Free Inst. Sce Trans., voL 3, pt. 4, p. 600,
pL 24, fig. 10.
type of this species came from the "Pliocene marls of the
oosahatchie, Florida." The shell is small, oval, inequilateral. The
mipture consists of very fine incremental lines, visible only under
unification. There are three anterior cardinal teeth in each valve
three posterior cardinals in the right valve and four in the left
. The posterior lateral tooth and opposing socket are slightly
the middle of the posterior side.
Oerrence: Upper Miocene: Cancellaria zone-borrow pit, Jack-
Bluff, Leon County, one right valve. Collected by the Florida
Survey.
see no difference between the Miocene and Pliocene shells.
Pleurodon gunteri Mansfield, n. sp.
Plate 2, Figures 4, 6
outline the shell of the new species is similar to that of Pleuro-
svoodii Dall, from which it differs slightly in having a narrower
shape. The principal difference between the two is in the
fiber of cardinal teeth. P. woodii has three posterior cardinal
whereas P. gunteri has only one. As compared with P. adamsi
[. a Recent species, P. gunteri has a shorter and smaller shell and
instead of two posterior cardinal teeth.
The external surface of the new species is smooth except for
re growth lines.
The new species is based upon a single right valve.
olotype (Cat. No. 371612, U. S. N. M.) measures: Length, 1.8
; height, 2.6 mm.
Iye locality: Station 12046, Vaughan Creek, upper locality,
County, Fla.
currency: Upper middle Miocene: Arca zone-known only from
te locality.
Superfamily ARCACEA
Family LIMOPSIDAE
Genus TRINACRIA C. Mayer, 1868
Trinacria meekii Dall?
Onimmature left valve of the genus Trinacria, from station 12046,
ghan Creek, upper locality, Walton County, may belong to T.
ekii Dall,42 a species described from the Oak Grove sand,
;'2Dall, W. H., Wagner Free Inst. SeL Trans., vol. 3, pt. 4, p. 604, pL 32, fig.





38 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

This species is reported by Gardner43 to occur also in the Shoa
River formation at one locality-station 3748, Sommerville mill rac
1 mile east of Argyle, Walton County.

Family ARCIDAE
Subfamily PECTUNCULINAE
Genus GLYCYMERIS Da Costa, 1778
Glycymeris pectinata (Gmelin)
Plate 3, Figures 1, 7
1792. Area pectinata Gmelin, Systema Naturae, vol. 6, p. 3313.
1841. Pectunculus aratus Conrad, Am. Jour. Sci., 1st ser., vol. 41, p. 346.
1845. Pectunculus aratus Conrad. Conrad, Fossils of the medial Tertiary of th
United States, p. 62, pL 34, fig. 2.
1853. Pectunculus pectiniformis D'Orbigny, in De la Sagra, Histoire physique
politique et naturelle de l'isle de Cuba, Mollusques de Cuba, vol. 2, p. 313.
(Not Lamarck, 1819.)
1856. Pectunculus aratus Conrad. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 50, pl. 17, figs. 6, 6a, 6b.
1858. Pectunculus charlestonensis Holmes, Post-Pleiocene fossils of South Carolina
p. 16, pL 3, fig. 5.
1886. Pectunculus pectinatus Gmelin. Dall, Harvard College Mus. Comp, Zoology
Bull, vol. 12, p. 239.
1898. Glycymeris pectinata Gmelin. Dall, Wagner Free Inst. ScL Trans, voL 3
pt. 4, p. 612.
1926. Glycymeris pectinata (Gmelin). Gardner, U. S. Geol. Survey Prof. Paper
142-A, p. 38, pl. 9, figs. 9-12. (Figured specimens from Neills Eddy Land.
ing, N. C.)
According to Dall,44 the Recent forms included under this species
have a rather wide range of mutations as to the number and width
of the ribs and the amount and sharpness of the truncation of the
shell.
Occurrence: Upper middle Miocene: Area zone-station 12046,
Vaughan Creek, upper locality, Walton County (common); station
12044, Bell farm, upper locality (one valve). Upper Miocene:
Ecphora zone-station 8862, half a mile northeast of Clarksville, Cal-
houn County (three valves); station 3418, from well at Bailey post
office, Calhoun County (one valve) ; station 3423, lower upper Miocene
bed at Jackson Bluff, Leon County (common). Cancellaria zone-
station 3671, 2 miles north of Hosford, Liberty County (one immature!
valve); station 3421, Harveys Creek, half a mile above abandoned
mill (one immature and corroded specimen; identification not cer-
tain).
The specimens from stations 8862 and 3418 are larger, more
rounded in outline, and less truncate than those from station 3423
and the majority of the living specimens and perhaps should be re-
garded as a subspecies of G. pectinata (Gmelin).
Outside occurrence: Miocene: Shoal River formation, Florida,

43Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-A, p. 22, 1926.
44Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 613, 1898.





SCHOCTAWHATCHEE PELECYPODS 39

tion .3742; Duplin marl, Carolinas. Pliocene: Waccamaw marl,
rolinas; Caloosahatchee marl, Florida. Pleistocene: South Caro-
a Recent: Cape Hatteras to Greytown, Nicaragua, and Barbados,
S2 to 175 fathoms.
.This species is reported from the Yorktown formation, Virginia
d North Carolina, by Gardner.45

Glycymeris americana (DeFrance)
Plate 2, Figure 7
9 Pectunculusamericanus DeFrance, Dictionnaire des Sciences Naturelles, vol.
S39, p. 225.
Pectunculus pulvinatus Conrad, Fossils of the Tertiary formations of North
SAmerica, p. 17, pl. 2, fig. 2. (Not Lamarck.)
Pectunculus lentilormis Conrad, Fossils of the Tertiary formations of North
America, 2nd ed, p. 36, note.
Pectunculus quinquerugatus Conrad, Am. Jour. Sci., slt ser., vol. 41, p. 346.
Pecanculus quinquerugatus Conrad. Conrad, Fossils of the medial Tertiary
Sof the United States, p. 63, pl. 34, fig. 3.
SPecunculus tricenarius Conrad, idem, p. 63, pL 35, fig. 1.
Pectunculus passes Conrad, idem, p. 64, pl. 35, fig. 3.
Pecunculus lentiformis Conrad. Conrad, idem, p. 64, pl. 36, fig. 1.
Pectnculus lentiformis Conrad. Tuomey and Holmes, Pleiocene fossils of
South Carolina, p. 48, pl. 17, fig. 2.
Pectunculus tranwersus Tuomey and Holmes, idem, p. 51, pl. 17, fig. 6 c.
(Not Deshayes or Dubois.)
Pectunulus quinquerugatus Conrad. Tuomey and Holmes, idem, p. 49,
pL 17, fig. 4.
Pectunculus carolinenensis Holmes, Post-Pleiocene fossils of South Carolina,
p. 15, pl. 3, fig. 4.
SPectanculus undatus (Linn6), Dall, Harvard College Mus. Comp. Zoology
SBull, vol. 12, No. 6, p. 238, in part.
SGlycymeris americana DeFrance. Dall, Wagner Free Inst, Sci. Trans., vol. 3,
pt. 4, p. 609 (part).
SGlycymeris americana DeFrance. Gardner and Aldrich, Acad. Nat. Sci
SPhiladelphia Proc., vol. 71, p. 18.

species has distinct radial striations. It is separated from
i parilis (Conrad), an earlier Miocene species, by its heavier
Proportionately broader shell.
ecurrence: Upper Miocene: Ecphora zone-station 8862, half
e northeast of Clarksville, Calhoun County (rare); station 3423,
upper Miocene bed at Jackson Bluff, Leon County (common).
ce iazone-station 1/966, Double Branch above highway
dge, Leon County (one valve); Harveys Creek, half a mile above
mdoned mill, Leon County (one valve; collected by Florida Geo-
Survey).
Outside occurrence: Upper Miocene: Yorktown formation, Vir-
very rare below fragmental series; Duplin marl, Carolinas.
e: Carolinas and Florida. Living off the coast from Cape
ras to Colombia in 15 to 60 fathoms.

Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-A, p. 38, 1926.





40 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Glycymeris subovata (Say)
Plate 2, Figure 10
1824. Pectunculus subovata Say, Acad. Nat. Sci Philadelphia Jour., 1st ser., voL
p. 140, pL 10, fig. 4.
1832. Pectunculus subovatus Say. Conrad, Fossil shells of the Tertiary formation
of North America, p. 17, pL 2, fig. 3.
1845. Pectunculus subovatus Say. Conrad, Fossils of the medial Tertiary of
United States, p. 62, pl. 34, fig. 1.
-1858. Pectunculus subovatus Say. Emmons, North Carolina Geol. Survey Re
p. 286, fig. 207.
1863. Axinnea (Pectunculus) subovata (Say). Conrad, Acad. Nat. ScL Philad
phia Proc. for 1862, p. 581.
1864. Axinaea subovata (Say) Conrad. Meek, Check list of the invertebrate fossil
of North America, Miocene: Smithsonian Misc. Coll., vol. 7, No. 183, p.
1898. Glycymeris subovata Say. Dall, Wagner Free Inst. Sci. Trans, vol. 3, pt.
p. 611. In part.
?1904. Glycvmeris subovata (Say). Glenn, Maryland Geol. Survey, Miocene, p. 3
pl. 107, figs. 3, 4.
1919. Glycymeris subovata Say. Gardner and Aldrich, Acad. Nat. Sci. Philadelp
Proc., vol. 71, p. 18.
1926. Glycymeris subovata (Say). Gardner, U. S. Geol. Survey Prof. Paper 142.
p. 35, pl. 8, figs. 3-8.
The type locality of Glycymeris subovata (Say) is recorded
Maryland, but it may be Virginia. Glenn46 writes:
The specimens in the Philadelphia Academy of Natural Sciences labeled "M
are similar in color to ones from the Yorktown, Va., region and have mate
between the teeth and in some holes in the shell very suggestive of the same loalit
I very much doubt their having come from Maryland.
The form figured by Glenn and reported from the Choptank fo
mation of Maryland is much smaller and has a higher beak than th
form in the later Miocene and may represent another species.
The earliest form from the St. Marys formation of Virginia appe
to be a new species of Glycymeris. This form is very similar to
waltonensis Gardner from the Shoal River formation of Florida.
Glycymeris subovata plagia Dall, a descendant of G. tumulus Cb
rad, occurs in the earliest faunal zone of the Yorktown formation o
Virginia, whereas G. subovatus tuomeyi Dall appears to range throu
out the Yorktown formation in Virginia and North Carolina.
The form from the Ecphora zone of Florida is similar to Glycymer
subovata plagia Dall.
Occurrence: Upper Miocene: Ecphora zone-upper bed at Al
Bluff (quite rare); station 1/954, half a mile northeast of Clarksvill
Calhoun County (two valves) ; station 3423, lower upper Miocene be
at Jackson Bluff, Leon County (abundant). Upper middle Miocene
Arca zone, Red Bay, Walton County fragmentall and incapable o
determination).
Outside occurrence: Miocene: Chipola formation and Shoal Riv
formation, Florida (Gardner); ?Choptank formation, Maryland; S
46Glenn, L. C., Maryland Geol. Survey, Miocene, p. 395, 1904.





CHOCTAWHATCHEE PELECYPODS


formation, Virginia; Yorktown formation, Virginia and Caro-
Duplin marl, Carolinas. This species does not appear to have
to the Pliocene.
Subfamily ARCINAE
Genus ARCA Linnaeus, 1758
Subgenus ARCA s. s.
Area (Area) occidentalis Philippi
Plate 2, Figure 2
Seecidenalis Philippi, Abbildungen und Beschreibungen Conchylien,
oL 3, p. 39, pi. 4, figs. 4a, 4b, 4c.
occidentalis Philippi. Dall, Wagner Free Inst. Sci. Trans, vol. 3, pt. 4,
p 620.
occidentalis Philippi. Sheldon, palaeontographica Americana, vol. 1,
No. 1, p. 8, pl. 1, figs. 8-11.
occidentalis Philippi Maury, Bull. Am. Paleontology, vol. 5, p. 327,
p. 55, fig. 3.
occidentalis Philippi Olsson, Bull. Am. Paleontology, voL 9, pp. 353-
5, pl 25, fig. 1.
(Arca) occidentalis Philippi. Woodring, Carnegie Inst. Washington
Pub. 366, p. 29, pl. 2, figs. 8, 9.
(Area) occidentalis Philippi. Gardner, U. S. Geol. Survey Prof. Paper
24A, p. 23.
shell of the typical Recent species is large, elongate, and
iteraL The posterior end is wider than the anterior. The ventral
soeterior margins are notched. The surface is discrepantly sculp.
kthe sculpture consisting mainly of primary and secondary
hI The cardinal area is wide and long, the ligament not extend-
outer edge of the area. The hinge line is long and nearly

inurrence: Upper Miocene: Cancellaria zone-tation 3421, Har-
Le half a mile above abandoned mill, Leon County (two

ptside occurrence: Miocene: Oak Grove and Shoal River for-
#i of Florida; Bowden marl, Jamaica; Gurabo formation, Santo
Igo; Gatun formation, Costa Rica. Pliocene: Caloosahatchee
SFlorida. Pleistocene: Florida Keys and West Indies. Living
LGulf of Mexico and the West Indies, northward to Hatteras and
ard to Bermuda, in 12 to 20 fathoms.
Subgenus BARBATIA Gray, 1847
Section PLAGIARCA Conrad, 1875
.Barbatia (Plagiarca) candida floridana Mansfield, n. subsp.
Plate 2, Figures 9, 11
all rather large, subtrapezoidal, moderately inflated. Anterior
a'broadly rounded; ventral margin weakly contracted opposite
Mk; posterior margin not entire but apparently obliquely trun-
Above and slightly extended below. Beak situated at about
or third of length of hinge line. Radial sculpture composed of

Ii,





42 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

many rather uniformly placed, narrow, weakly nodulous, distinct ri
separated by interspaces about equal in width to ribs. Ribs mesia
incised on posterior ridge and more widely separated on lower anter
slope. Cardial area rather wide, lanceolate, weakly concave, strong
marked by nine oblique grooves, those on anterior side being und
lated. Teeth at both extremities much larger, oblique, and double
Holotype, left valve (Cat. No. 371117, U. S. N. M.), measure
Length, 55 mm.; maximum height, 34 mm.; diameter, 12.2 mm.
This subspecies differs from Barbatia candida candida Gmelin
having a proportionately shorter and more inflated shell with a le
emarginate ventral margin and a less crowded radial sculpture.
Occurrence: Upper Miocene: Cancellaria zone-Harveys Cree
half a mile above abandoned mill, Leon County, Fla.
Only one left valve, the type of the subspecies, collected by the Flo
ida Geological Survey, is at hand.

Section CALLOARCA Gray, 1857
Barbatia (Calloarca) leonensis Mansfield, n. sp.
Plate 5, Figures 1, 3, 5
Shell thin, transversely elongate, mesially compressed. Be
low, broad, and situated near the anterior sixth of hinge line.
terior region of shell short; posterior region long and posterior
ventrally produced. Anterior lateral margin broadly rounded; ve
tral margin diverging posteriorly from hinge line; posterior later
margin gently sloping from dorsal and narrowly rounding into ventr
Sculpture composed of about 50 nearly flat, smooth, closely and
formly placed, distally incised ribs and very weak concentric grow
lines, which produce low elevations only on the anterior and posterio
slopes. Cardinal area concave, wider in front and scored at the po
terior end by two or three oblique grooves. Hinge shorter than she
Teeth in two series, separated by an edentulous gap. The small
cotype, right valve, has 5 irregular teeth in the anterior series-th
anterior being the larger-and about 17 in the posterior series.
Cotypes (Cat. No. 371118, U. S. N. M.) measure: Larger, broken
right valve: Length, 26 mm.; height, 12 mm.; diameter, 7 mm
Smaller and nearly perfect right valve: Length, 14 mm.; height, f
mm.; diameter, 3.3 mm.
The new species belongs to the same section as "Barbatia (Cucua
laria) taeniata" Dall,47 a Pliocene species, and "Barbatia (Calloarca)
phalacra" Dall,48 a species occurring in the Chipola and Oak Grove
formations of Florida.
47Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 631, pl. 25, figs.
la, 1898.
48Idem, p. 626, pl. 33, fig. 3.





CHOCTAWHATCHEE PELECYPODS 43
*'
bat 'heterodonta (Deshayes), regarded as the type of the
w.CucuUaria, has a different type of hinge teeth from that of
ecan species above cited. Barbatia alternate (Sowerby), a
. west coast species, is the type of the section Caloarca Gray.
ie teeth of the new species are similar to those of B. alternate.
iirner placed Barbatia phalacra Dall under the section
f r. Conrad and regarded the section Calloarca as a synonym
"section Acar. Area gradata Broderip and Sowerby was desig-
ithe type of the section Acar by Woodring.5 Area alternate dif-
om Area gradata in having a much wider edentulous gap be.
Ithe two series of teeth and a different type of sculpture. The
cies appear to be sufficiently unlike to represent different

izrence: Upper Miocene: Cancellaria zone-Harveys Creek,
mile above abandoned mill, Leon County, Fla., type locality
; station 1/422, Hamlin Pond, Washington County (rare).
itde occurrence: Upper Miocene, Muldrow Place, 5 miles
east of Mayesville, Sumter County, S. C.

Section GRANOARCA Conrad, 1863
Barbatia (Granoarca) propatula Conrad
Plate 4, Figures 1, 2, 3
propatula Conrad, Aead. Nat. Sei. Philadelphia Proc., vol. 1, p. 323.
propatula Conrad. Conrad, Fossils of the medial Tertiary of the United
SSlate, p. 61. pl. 32, fig. 1.
a hians Tuomey and Holmes. Pleiocene fossils of South Carolina, p. 34,
pL 14, figL 4,5. (Not Bronn, 1842, or Reeve, 1844).
baa (Granoarca) propatula Conrad. Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, pp. 290, 580.
(Granoarca) propatula Conrad. Tryon, Structural and systematic con-
.ehology, vol. 3, p. 254, pl. 129, fig. 5.
batia (Granoarca) propatula Conrad. Dall, Wagner Free Inst. Sci. Trans.,
'voL 3, pt. 4, p. 627.
hian Tuomey and Holmes (not Bronn or Reeve). Whitfield and
Hovey, Am. Nat. Hist. Bull., vol. 11, pt. 4, pp. 444-447.
a (Barbatia) propatula Conrad. Sheldon, Palaeontographica Americana,
vol. 1, No. 1, p. 18. pl. 4, fig. 1.
e species is characterized by its elongate, posteriorly expanding,
ally depressed shell, and ribs which are nearly flat except on the
mrior shoulder, where they are larger and more rounded. Ribs
ly weakly medially sulcate; concentric sculpture of fine threads
h produce small granules on the anterior slope of the umbonal
m. Teeth, at posterior extremity, granular or tuberculate, espe-
y on senile specimens.
IGardner, Julia, The molluscan fauna of the Alum Bluff group of Florida:
GeoL Survey Prof. Paper 142-A, p. 26, 1926.
)Woodring, W. P, Miocene mollusks from Bowden, Jamaica: Carnegie Inst.
Ington Pub. 366, p. 36, 1925.
,'.





44 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Conrad established the section Granoarca on account of the gr
ular breaking up of the distal teeth. This modification appears
be the result of senility. Young shells do not possess this, but as
shell gets older and consequently heavier these teeth become bro
up and granular. This species probably is a descendant of the
Marys species Area (Barbatia) virginiae Wagner. Area compyla D
a characteristic Pliocene species, belongs to the same group and
pears to be a descendant of Barbatia propatula.
Occurrence: Upper Miocene: Cancellaria zone-station 117
borrow pit near Jackson Bluff, Leon County (abundant); static
4993, from well 1 mile west of Holland post office, Leon Cou
(?rare); Harveys Creek, half a mile above the abandoned mill,
County (two corroded specimens, which are much heavier for
same size than those from the other localities and may be the ad
of the following subspecies).
Outside occurrence: Miocene: Yorktown formation of Virg
at Petersburg, City Point, and Ware River, Gloucester County (Co
rad, Tuomey, and Ruffin) ; Duplin marl, Darlington, S. C. Specim
from Ware River, Va., and Darlington, S. C., are deposited in
collection of the United States National Museum and are inseparab
from the Florida specimens.

Barbatia (Granoarca) propatula busana Harris
Plate 3, Figures 2, 4, 6
1893. Area, young of floridana? Harris, Texas Geol. Survey Fourth Ann. R
p. 121.
1895. Area transversa var. busana Harris, Bull. Am. Paleontology, vol. 1, No. 3,
There are six small specimens in the collection of the United Sta
National Museum labeled Area var. busana Harris, taken from the de
well at Galveston at a depth of 2,552 to 2,600 feet, which compare wi
specimens from four localities in the upper Miocene of Florida.
Florida specimens are much larger than the specimens from the dee
well at Galveston. The Florida form appears to be more closely
related to Barbatia (Granoarca) propatula Conrad than to "Arc
transversa" Say. i
Occurrence: Upper Miocene: Cancellaria zone-station 342
Harveys Creek, half a mile above abandoned mill, Leon County (con
mon); station 1/966, Double Branch above highway bridge, Leq
County (rare); station 8176, "Deadens," Washington County (rare)
stations 3671, 3672, 2 and 234 miles north and northwest of Hosforo
Liberty County (rare).





CHOCTAWHATCHEE PELECYPODS 45

Subgenus FOSSULARCA Cossmann, 1887
Area (Fossularca) adamsi (Shuttleworth MS.) Dall
Plate 7, Figures 1, 2, 3
coelata Conrad. Fossils of the medial Tertiary of the United States,
p. 61, pl. 32, fig. 2. (Not Arca coelata Reeve, 1844.)
rbaa (Acar) coelata Conrad (not Reeve). Conrad, Acad. Nat. Sci. Phil.
adelphia Proc. for 1862, vol. 14, p. 580.
adamsi Shuttleworth. Dall, Harvard Coll. Mus. Comp. Zoology BulL,
voL 12, p. 243.
(Acar) adamsii Shuttleworth MS.? Smith, E. A., Linnaean Soc. Jour.
Zoology, vol. 20, p. 499, pl. 30, figs. 6, 6a.
rbatia (Fossularca) adamsi (Shuttleworth) Smith. Dall, Wagner Free
Inst. Sci Trans., vol. 3, pt. 4, p. 629.
ca adamsi (Shuttleworth) Smith. Sheldon, Palaeontographica Americana,
voL 1. No. 1, p. 22, pl. 4, figs. 16-18, pl. 5, fig. 1.
(Barbatia) adamsi (Shuttleworth). Gardner and Aldrich, Acad. Nat.
SeL Philadelphia Proc., vol. 71, p. 18.
esularca (Fossularca) adamsi sawkinsi Woodring, Carnegie Inst. Washing-
ton Pub. 366, p. 51, pL 5, figs. 16, 17. (Subspecific name sawkinsi sup-
pressed, Carnegie Inst. Washington Pub. 385, p. 18, 1928.)
rbauia (Fossularca) adamsi (Shnttleworth MS.) Dall. Gardner, U. S. Geol.
Survey Prof. Paper 142-A, p. 28, pl. 5, figs. 1-4.
species is recognized by its trapezoidal outline, the emarginate
al margin, its cancellate and denticulate sculpture, and diamond-
Smuscular impression beneath the beaks.
jcurrence: Upper Miocene: Cancellaria zone station 3421,
iys Creek, half a mile above the abandoned mill, Leon County
mon).
inside occurrence: This species has been reported from the
Miocene to the Recent. In the Recent, it ranges from Cape
to Brazil in 10 to 35 fathoms.

Subgenus NOETIA Gray, 1857
Area (Noetia) incile Say
Plate 6, Figure 6
incile Say, Acad. Nat. Sci. Philadelphia Jour, 1st ser., voL 4, p. 139, pl.
10, fig. 3.
incile Say. Conrad, Fossil shells of the Tertiary formations of North
America, p. 16, pl. 2, fig. 1.
Sincile Say. Conrad, Fossils of the medial Tertiary of the United States,
pt. 2, p. 56, pl. 29, fig. 5.
incile Say. Tuomey and Holmes, Pleiocene fossils of South Carolina,
35, pL 14, figs. 6,7.
incite Say. Emmons, North Carolina Geol. Survey Rept., p. 284.
dia (Area) incite Say. Conrad, Acad. Nat. Sci Philadelphia
Proc. for 1862, vol. 14, p. 580.
a ncite (Say). Meek, Check list of the invertebrate fossils of North
America, Miocene: Smithsonian Misc. Coll., voL 7, No. 183, p. 6.
ois protexta Conrad, North Carolina Geol. Survey Rept., vol. 1, app.,
p. 19, p 3, fig. 5.
(Noeaia) incile Say. Dall, Wagner Free Inst SeL Trans, voL 3, pt. 4,
p. 63L
(Noesia) incite Say. Sheldon, Palaeontographica Americana, voL 1,
No. 1, p. 25, pL 5, figs. 18.25.
(Noetia) incile Say. Gardner and Aldrich, Acad. Nat. Sci. Philadelphia
vol. 71, p. 18.





46 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The type of this species probably came from Virginia, altho
it is reported from Maryland by Say. I know of no later collect
that has confirmed the presence of this species in the Maryl
Miocene.
This species is closely related to Area (Noetia) limula Conrad, i
it has a narrower and shorter cardinal area, longer and straighter
line, and a smaller shell than that species.
Occurrence: Upper Miocene: Ecphora zone-station 3423, lo
upper Miocene bed at Jackson Bluff, Leon County (two specimen
Cancellaria zone-station 3422, uppermost fossiliferous bed at Jacki
Bluff (rare); station 3672, 23/ miles northwest of Hosford, Libe
County (rare); station 3421, Harveys Creek, half a mile above ab
doned mill, Leon County (rare).
The specimens from station 3423 have the posterior dorsal a
more produced and the posterior margin more deeply notched th
the specimens from the other localities.
Outside occurrence: Upper Miocene: Yorktown formation, V
ginia and North Carolina. Duplin marl, Carolinas. Not known
later deposits.

Subgenus ANADARA Gray, 1847
Area (Anadara) idonea alumensis Mansfield, n. subsp.
Plate 6, Figures 1, 2, 5
This new subspecies was placed under "Scapharca (Scaphare
idonea" Conrad by Dall51 and by Sheldon.52
This subspecies differs in general from Area idonea idonea in
contour of the umbonal area, in the nature of the sculpture on t
right valve, and in having fewer ribs, and a more prosogyrate bea
Conrad53 states that A. idonea from Maryland has about 25 ribs, bi
the average number of ribs on the specimens from the St. Marys fo
mation of Maryland is 30. This new subspecies has from 24 to 2
ribs. The right valve of the St. Marys form has a more prominei
posterior ridge, a more depressed and flatter area in front of th
ridge, and ribs over the middle of the shell which are less high]
sculptured. The left valves of the two forms are more similar, in
the St. Marys form shows a more depressed area in front of the po
terior ridge.
Cotypes (Cat. No. 114845, U. S. N. M.) measure: Right valve
Length, 43 mm.; height, 38 mm.; diameter, 18 mm. Left valvE
Length, 45 mm.; height, 41 mm.; diameter, 18 mm.
e5Dall, W. H., Wagner Free Inst. Sci. Trans, vol. 3, pt. 4, p. 639, 1898.
52Sheldon, Pearl G., Palaeontographica Americana, vol. 1, pt. 1, p. 41, 1917.
53Conrad, T. A., Fossil shells of the Tertiary formations of North Americ
p. 16, 1832.





S CHOCTAWHATCHEE PELECYPODS 47

specimens less well preserved are much larger than the
one valve measuring in length, 61 mm.; height, 57 mm.;
S26 mm.
arrence: Upper Miocene: Ecphora zone-upper bed at Alum
libertyy County, type locality (common); station 1/962, cut in
id leading to Watsons Landing, Liberty County (rare?); Per-
s old place, Walton County (one corroded valve, identifica-
ertain).
Arca (Anadara) idonea harveyensis Mansfield, n. subsp.
Plate 6, Figures 3, 4, 7
large, semiquadrate, strongly inflated, moderately depressed
Sof the posterior ridge, and weakly extended at the postero-
'angle. Anterior end full, nearly as high as posterior end.
~r. slope truncate, slightly expanded near margin; area in
posterior ridge weakly depressed-more so on right valve than
anterior slope full and well rounded. Ribs, 27 on right valve
on left valve, wide, separated by interspaces, strongly crenu-
,left valve and weakly crenulated behind posterior ridge on
rlve, those on anterior part being mesially grooved. Beaks
.at about anterior third of hinge line, strongly prosogyrate.
Area rather wide, marked with four to five concentric grooves.
"ine nearly straight. The description is made from two speci-
Sright and a left valve from the same locality, the right valve
auch larger.
types (Cat. No. 371125, U. S. N. M.) measure: Right valve:
.75 mm.; height, 68 mm.; diameter, 33 mm. Left valve:
8 mm.; height, 52 mm.; diameter, 25 mm.
iabsepecies differs from Area idonea idonea in its more quad-
~m and in having fewer and more crenulated ribs. It differs
idonea alumensis in having a fuller and wider anterior ex-
flatter beaks, and in having one to two more radials.
nurrence: Upper Miocene: Ecphora zone?-station 4993, well
[olland post office, Leon County (common). Cancellaria zone-
s Creek, half a mile above the abandoned mill, Leon County,
Locality (rare); station 3422, uppermost bed at Jackson Bluff,
countyy (abundant); station 1/953, 1 mile below Econfina
q Bay County (rare?); stations 3671, 3672, 2 miles north and
iles northwest of Hosford, Liberty County (common), station
;Hamlin Pond, Washington County (common); station 8176,
ens," Washington County (common).
i specimens from stations 3671 and 3672 have 28 or 29 ribs and
eimens from other localities about 27 ribs. The specimens of
w subspecies, especially those from stations 3671 and 3672,
k...





48 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

more closely resemble specimens in the Virginia Miocene at Urban
and in beds at other places which are believed to carry a fauna rep
senting the highest part of the St. Marys formation in Virginia.

Area (Anadara) rubisiniana Mansfield
Plate 7, Figures 5, 6, 7
1916. Arca (Scapharca) staminea rubisiniana Mansfield, U. S. Nat. Mus. Proe,
51, p. 603, pL 113, figs. 1, 3, 1916.
This species is related to A. staminea Say, a species confined to t
Choptank formation in Maryland and Virginia, but differs in havij
a straighter base line, a shallower depression in front of the poster
ridge, and ribs that show less tendency to subdivision by incised lon
tudinal lines.
"Diluvarca (Diluvarca)" waltonia Gardner, a species from
Shoal River formation of Florida, is closely related to A. rubisinial
but has a smaller shell, with ribs that are longitudinally divided 4
some parts of the shell, and a relatively narrower posterior side. I
A. rubisiniana appears to be more closely related to the She
River and Choptank forms than to the form in the St. Marys form
tion of Maryland or Virginia, although this appearance may be di
to environment rather than to the relative age of the deposits. .
Occurrence: Upper middle Miocene: Area zone-vicinity of Re
Bay, Walton County, Fla., type locality; station 12046, Vaughan Cree
upper locality, Walton County (common); 12047, Vaughan Cree
lower locality (common); station 12044, Bell farm, upper local
Walton County (rare) ; station 12045, Bell farm, lower locality (rare
Yoldia zone-station 12060, Frazier farm, Walton County (rare)
tion 12718, upper bed at Chester Spence farm, Walton County (qui
common). Station 12718 appears to be the base of the Yoldia zon

Area (Anadara) sellardsi Mansfield, n. sp.
Plate 7, Figures 8, 9
Shell large, heavy, thick, semiquadrate, transversely elongate, wil
a strong and rather high and protruding beak. Anterior side narrow
rounded; posterior side steeply declining to margin; back broad
rounded. Posterior and anterior margins subparallel, ventral marg
diverging from hinge line posteriorly. Surface ornamented by abol
26 strong radials about half as wide as the interspaces. Cardinal an
very wide, marked longitudinally by many wavy, medially arch<
grooves. Posterior teeth curved downward. The specimen is corrode
and the finer sculpture on ribs, if formerly present, is not discernibi
Type (Cat. No. 371127, U. S. N. M.), right valve, measures: Lengt
75 mm.; height, 88 mm.; diameter, 37 mm.





CHOCTAWHATCHEE PELECYPODS


arrence: Upper Miocene: Cancellaria zone-station 3421, Har-
e half a mile above the abandoned mill, Leon County, Fla.
ht valve collected by Dr. T. W. Vaughan and two right valves
by the Florida Geological Survey).
ecies is named in honor of Dr. E. H. Sellards, former State
of Florida.

Area (Anadara) callicestosa (Dall)
Plate 5, Figures 7, 8
ha (Scapharca) callicestosa Dall, Wagner Free Inst. Sci. Trans., voL
t. 4, p. 638, pl. 34, figs. 17, 18.
(Scapharca) callicestosa Dall. Sheldon, Palaeontographica Americana,
1o, No. 1, p. 43, pl. 10, figs. 3-5.

pe specimen of this species, a left valve, came from the
d (Miocene) at Gaskins Wharf, on Nansemond River, 16
o Suffolk, Va." The species is characterized by its thin,
idal-shaped shell and by the nature of the sculpture on the
e ribs. This sculpture consists of four longitudinal threads,
pair being the stronger. The combined radial and concentric
Gives the surface of the ribs a reticulate and punctate appear-
mbling that on the ribs of some Pectens. The ribs on the
early part of the shell are beaded. The type specimen has

-rrence: Upper Miocene: Ecphora zone-station 3423, lower
Miocene bed at Jackson Bluff, Leon County, Fla. (six valves).
tria zone-station 3421, Harveys Creek, half a mile above the
bed mill, Leon County (ten valves, some collected by Dr. T. W.
s, ome by the Florida Geological Survey, and some by W. C.
ld).
ide occurrence: Upper Miocene: Duplin marl of North Caro-

Florida specimens from the Cancellaria zone show the fol-
number of ribs: Left valve, three with 34, two with 35, and one
# right valve, four with 34. Most of the Florida specimens
Fger -than the type, the right valve of one specimen measuring
th, 67 mm.; height, 66 mm.; diameter, 22 mm.
; six valves collected at station 3423 are not perfect. When
specimens are obtained from this zone they may show a sub-
""relationship to those from the higher zone. They have a
shorter hinge line and stronger, more rounded radials, with an
tion of more and finer longitudinal lines on the tops of the ribs
e specimens from the Cancellaria zone.

I





50 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Area (Anadara) lienosa Say
Plate 3, Figure 8
1832. Arca lienosa Say, American conchology, No. 4, pL 36, fig. 1.
1837. Arca protracta Rogers, Am. Philos. Soc. Trans., new ser., voL 5,
Described.
1839. Arca protracta Rogers, idem, vol. 6, pl. 26, fig. 5.
1845. Area (Anomalocardia) protracta Rogers. Conrad, Fossils of the
Tertiary of the United States, p. 58, pL 30, fig. 5.
1856. Area lienosa Say. Tuomey and Holmes, Pleiocene fossils of South
p. 40, pl. 15, figs. 2, 3.
1858. Area lienosa Say. Emmons, North Carolina Geol. Survey Rept., p. 284,
1863. Scapharca (Area) lienosa Conrad. Conrad, Acad. Nat. Sci. Philad
Proc. for 1862, p. 579.
1887. Arca lienosa Say. Heilprin, Wagner Free Inst. Sci. Trans., vol. 1,
(In part.)
1898. Scapharca (Scapharca) lienosa Say. Dall, Wagner Free Inst. Sci.
3, pt. 4, p. 636.
1907. Area protracta Rogers. Cushman, Boston Soc. Nat. Hist. Proc., vol. 33,
1917. Area (Scapharca) lienosa Say. Sheldon, Palaeontographica American
1,-p. 35, pl. 7, figs. 26-28; pl. 8, figs. 1, 2.
1919. Area (Scapharca) lienosa Say. Gardner and Aldrich, Acad. Nat.
adelphia Proc., vol. 71, p. 18.
The shell of this species is usually rather thin and transv
oblong; beaks mesially sulcate; ribs, about 40, beaded, each
deep median groove and a finer secondary groove on each side
main groove. Cardinal area rather narrow, longitudinally
with four to six broadly concentric grooves. Hinge line
straight, teeth increasing in strength toward the extremities.
This species appears to have thrived best under subtropical
editions. The individuals were very rare in the cool temperate
of the Chesapeake group but became more abundant in the w
temperate water of the later Yorktown and Duplin formations.
Occurrence: Upper Miocene: Ecphora zone -near Clar
Calhoun County (rare); station 2210, upper bed at Alum Bluff,
erty County (rare) ; station 3423, lower upper Miocene bed at Ja
Bluff, Leon County (common). Cancellaria zone-station 3672,
miles northwest of Hosford, Liberty County (rare); station
Gully Pond, Washington County (rare); station 11732, borrow
near Jackson Bluff, Leon County (rare) ; station 1/966, Double Br
above highway bridge, Leon County (one valve); station 3421,1
veys Creek, half a mile above abandoned mill, Leon County (C
mon). Ecphora or Cancellaria zone-station 1/951, Red Head
Washington County (one cast and identification uncertain).
The specimens from the Cancellaria zone are usually larger
thinner than those from the Ecphora zone.
Outside occurrence: Miocene: Yorktown formation, Virg
Appears not to occur earlier than in the bed directly beneath the
mental series. Duplin marl, North and South Carolina. Plio
Waccamaw district, South Carolina, and Caloosahatchee River
Alligator and Shell Creeks, Florida.





CHOCTAWHATCHEE PELECYPODS 51

Area (Anadara) improcera Conrad
Plate 3, Figures 3, 5
improcera Conrad, Fossils of the medial Tertiary of the United States,
60, pL 31, fig. 5.
S(Area) improcera Conrad. Conrad, Acad. Nat. Sci Philadelphia
o. for 1862, voL 14, p. 579.
Splicasura (juvenis) Heilprin, Acad. Nat. Sci. Philadelphia Proc. for
1, p. 451. (Not Conrad.)
msrca (Scapharca) improcera Conrad. Dall, Wagner Free Inst. ScL
anvoL 3, pt. 4, p. 643.
ea (Scapharca) improcera Conrad. Sheldon, Palaeontographica Americana,
1, No. 1, p. 44, pl. 10, figs. 9-16.
i-ocality of this species is recorded by Conrad in 1845 as "Wil-
N. C." The species is characterized by its nearly quadrate
father high beak, and ribs usually without nodules.
mnrence: Upper Miocene: Cancellaria zone-station 1/966,
Branch, above highway bridge, Leon County (two valves);
Fpit near Jackson Bluff, Leon County (two specimens); sta-
%2, highest upper Miocene bed at Jackson Bluff, Leon County
;gment).
'ide occurrence: Miocene: Yorktown formation, comminuted
d higher, Virginia and North Carolina; Duplin marl, Caro-
?Pliocene of Carolinas and Florida. Specimens formerly
ed as A. improcera, from the Pliocene, appear more nearly
p A. compyla Dall.

Arca (Anadara) aresta Dall
f" Plate 17, Figure 2
(Anadara) aresta Dall, Wagner Free Inst. ScL Trans, voL 3, pt. 4,
S655, pL 33, fig. 2.
6l (Anadara) aresta Dall. Sheldon, Palaeontographica Americana, voL 1,
F. 1, p. 53, pl. 12, figs. 9-11.
dara aresta Dall. Cooke and Mossom, Florida Geol. Survey Twentieth
RniL Rept., pl. 17, fig. 2.
Species is characterized by its rather strongly medially inflated
cate base, nearly straight hinge line, and narrow and distinct
PiaS species is closely related to Arca costaricensis Olsson, from
d hill 2, Banana River, and Zone 7, Pumbri Creek, Costa Rica.
prrence: Upper Miocene: Ecphora zone-upper bed at Alum
Liberty County, Fla., type locality (common); station 3423,
Ipper Miocene bed at Jackson Bluff, Leon County (one valve);
12048, Permenter's old place, Alaqua Creek, Walton County
ion); Clarksville, Calhoun County (rare).
I specimens from station 12048 are larger and have about three
jibs than the specimens from the type locality but in other
are the same.
ke_________






52 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Area (Anadara) propearesta Mansfield, n. sp.
Plate 5, Figures 2, 4, 6
Shell rather small, semiovate, elongate, low, and inequilateral.
Beaks low, weakly impressed mesially at tip and nearly flat behind,
and located at anterior third of. length. Ribs, 28 in number, rather
narrow, flat-topped, nearly equal in size and nearly uniformly sep-
arated by round-bottomed interspaces. The ribs over the posterior
shoulder and anterior slope are a little wider than those over the
middle of shell. Concentric sculpture composed of fine continuous
growth lines, giving the early part of the shell a faintly reticulate
appearance. Distally the concentric sculpture is less well defined
and consists of a few narrow elevations located mainly on the anterior
slope. Cardinal area well defined, lanceolate, narrow, wider in front
of inturned beak, grooved only on posterior area; hinge line nearly
straight, weakly arched upward medially; teeth thin, blunt, arranged
in two series-an anterior series with 33 teeth and a posterior series
with 45 teeth.
Holotype, a left valve (Cat. No. 371124, U. S. N. M.) measures in
height, 19.5 mm.; length, 35 mm.; diameter, 9 mm. Paratype, a right
valve from station 3422, measures in height, 14 mm.; length,-23 mm.;
diameter, 5 mm.
The new species has fewer ribs than A. lienosa Say and also lacks
the incised and beaded ribs that are characteristic of Say's species.
Occurrence: Upper middle Miocene: Area zone-station 12046,
Vaughan Creek, upper locality, Walton County (three small valves
and identification uncertain). Upper Miocene: Cancellaria zone-
station 11732, borrow pit near Jackson Bluff, Leon County, type
locality (seven valves); station 3422, upper bed at Jackson Bluff (one
right valve).
Area (Anadara) campsa Dall
Plate 17, Figures 3a, 3b
1898. Scapharca (Anadara) campsa Dall, Wagner Free Inst. Sci. Trans., vol. 3. pt. 4,
p. 656, pl. 32, fig. 21.
1917. Arca (Anadara) campsa Dall. Sheldon, Palaeontographica Americana, vol. 1,
No. 1, p. 54, pl. 12. fig. 12; pl. 13, figs. 1-3.
1929. Anadara camps Dall. Cooke and Mossom, Florida Geol. Survey Twentieth
Ann. Rept, pL 17, fig. 3.
The shell of this species is distinguished from Arca aresta by its
larger size, less arcuate base, fattened and mesially depressed beak
and middle part of the shell, and by its more widely separated ribs.
Occurrence: Upper Miocene: Ecphora zone-upper bed at Alum
Bluff, Liberty County, type locality (common); station 3423, lower
upper Miocene bed at Jackson Bluff, Leon County (common); station
1/954, half a mile northeast of Clarksville, Calhoun County (one
valve). Cancellaria zone-station 8176, "Deadens," southeast of





CHOCTAWHATCHEE PELECYPODS 53

Greenhead, Washington County (two valves); borrow pit near Jack-
son Bluff (one valve, collected by Mr. Herman Gunter).
Subgenus CUNEARCA Dall, 1898
Area (Cunearca) scalaris Conrad
Plate 7, Figure 4
1843. Arca scalaris Conrad, Acad. Nat. Sci. Philadelphia Proc., voL 1, p. 324.
1845. Area scalaris Conrad. Conrad, Fossils of the medial Tertiary of the United
States, p. 59, pl. 31, fig. 1.
1856. Area scalaris Conrad. Tuomey and Holmes, Pleiocene fossils of South Caro-
lina, p. 43, pl. 16, figs. 1, 2.
1863. Scapharca (Arca) scalaris Conrad. Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, p. 580.
1898. Scapharca (Cunearca) scalaris Conrad. Dall, Wagner Free Inst. Sci. Trans.,
vol. 3, pt. 4, p. 634.
1917. Area (Cunearca) scalaris Conrad. Sheldon, Palaeontographica Americana,
vol. 1, No. 1, p. 57, pl. 13, figs. 10, 11.
1919. Area (Scapharca) scalaris Conrad. Gardner and Aldrich, Acad. Nat. Sci
Philadelphia Proc., voL 71, p. 18.
The type locality of this species, according to Conrad, 1843, is
Petersburg, Va. The shell is obliquely rhomboidal, of medium size,
equivalve, ornamented with about 23 broad, square, crenulated, prom-
inent ribs separated by narrower, channeled, and smooth interspaces.
The ligamental area has weak transverse striae. This species differs
from its descendant Arca (Cunearca) scalarina Heilprin in lacking
the intermediate rib, which is especially prominent on the right valve
of that species.
Occurrence: Upper Miocene: Ecphora zone-upper bed at Alum
Bluff, Liberty County (rare). Cancellaria zone-station 3671, 2 miles
north of Hosford, Liberty County (many young specimens); station
3672, 23/ miles northwest of Hosford (young); station 1/946, Harveys
Creek, half a mile above abandoned mill, Leon County (one left
valve).
Outside occurrence: Upper Miocene: Yorktown formation, Vir-
ginia. Duplin marl, Carolinas.
Superfamily PTERIACEA
Family PINNIDAE
Genus ATRINA Gray, 1847
Atrina n. sp.?
Imperfect specimens of the genus Atrina were collected from the
upper Miocene of Florida. These may represent a new species, but
the specimens in hand are too poorly preserved to determine all the
characters.
The Florida specimens appear to be the same species as a fragment
from the Duplin marl at Magnolia, N. C., which Dall" united with
Atrina harrisii Dall, a species described from the Choptank formation
of Maryland.
54Dall, W. H., Wagner Free Inst. ScL Trans., vol. 3, pt. 4, p. 663, 1898.





54 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The Florida specimens are more convex and have stronger longi-
tudinal, elevated lines on the dorsal region than Atrina harrisii and
probably represent another species.
Occurrence: Upper Miocene: Cancellaria zone-Harveys Creek,
half a mile above the abandoned mill, Leon County; ?station 1/422,
Hamlin Pond, Washington County (one fragment).
Outside occurrence: Upper Miocene: Duplin marl, Magnolia, N.
C., and 1 mile south of Darlington, S. C.

Family PTERIIDAE
Genus PTERIA Scopoli, 1777
Pteria multangula (H. C. Lea)?
Dall55 identified a specimen collected from the upper bed at Alum
Bluff, Fla., as Pteria multangula (H. C. Lea). The type56 of Lea's
species came from Petersburg, Va. Lea's type is a small specimen,
and I am not sure that the Alum Bluff specimen should be specifically
united with it. There are no specimens of this genus from Petersburg
in the collection of the United States National Museum. A number
of specimens, none of which is entire, were obtained at three localities
in the Miocene of Florida and probably represent the same species.
The specimens appear to be nearly related to Pteria colymbus (Bol-
ten), a species reported by DalP7 as occurring in time from the Plio-
cene to the Recent.
Occurrence: Upper Miocene: Ecphora zone-upper bed at Alum
Bluff, Liberty County, Fla. (two fragments); station 1/962, cut in
old road leading to Watsons Landing, Liberty County (two frag-
ments); station 3423, lower upper Miocene bed at Jackson Bluff,
Leon County (three fragments).
Superfamily OSTRACEA
Family OSTREIDAE
Genus OSTREA Linnaeus, 1758
Ostrea disparilis Conrad
Plate 8, Figures 1, 6
1840. Ostrea disparilis Conrad, Fossils of the medial Tertiary of the United States,
p. 51, pl. 26.
1856. Ostrea raveneliana Tuomey and Holmes, Pleiocene fossils of South Carolina,
p. 21, pl. 6, figs. 1-3.
1898. Ostrea compressirostra Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 679.
(Not Say, 1824, in part.).
1903. Ostrea compressirostra Dall, idem, pt. 6, pp. 1597, 1602. (Not Say, 1824.)
1919. Ostrea compressirostra Gardner and Aldrich (not Say, 1824), Acad. Nat. Sci.
Philadelphia Proc., vol. 71, p. 18 (in list).
The type locality of Ostrea disparilis is near City Point, Va. This
species apparently came from the upper Miocene bed at this place.
55Dall, W. H., Wagner Free Inst. Sci. Trans, voL 3, pt. 4, p. 669, 1898.
5eLea. H. C., Am. rhilos. Soc. Trans., vol. 9, p. 245, pl. 35, fig. 31, 1845.
57Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 670, 1898.






CHOCTAWHATCHEE PELECYPODS


Dal5" placed Ostrea disparilis Conrad in synonymy with 0. compres-
sirostra Say, an Eocene species. 0. compressirostra differs from O.
disparilis in having a more elevated umbonal area-a character espe-
cially well shown on the nearly flat upper valve-and stronger radials
and more elevated laminae on the lower valve.
Occurrence: Upper Miocene: Ecphora zone-upper bed at Alum
Bluff, Liberty County; station 1/962, cut in old road to Watsons Land-
ing, Liberty County; station 1/954, half a mile northeast of Clarks-
ville, Calhoun County; station 3423, lower upper Miocene bed at
Jackson Bluff, Leon County; station 1/965, lower upper Miocene bed
at the abandoned mill on Harveys Creek, Leon County. Cancellaria
zone-station 3421, half a mile above the abandoned mill on Harveys
Creek; station 11732, borrow pit, Jackson Bluff, Leon County; station
1/422, Hamlin Pond, Washington County; station 1/706, Gully Pond,
Washington County; station 1/961, near Woods, Liberty County;
station 3671, 2 miles north of Hosford, Liberty County; station 3672,
24 miles northwest of Hosford; station 1/953, 1 mile below Econfina
bridge, Bay County.
Outside occurrence: Miocene: St. Marys formation, Virginia;
Yorktown formation, Virginia and North Carolina; Duplin marl,
Carolinas.

Ostrea haitensis Sowerby?
Plate 9, Figure 1
1916. Ostrea (yo.) sp, Mansfield, U. S. Nat. Mus. Proc., vol. 51, p. 601.
One large corroded specimen representing an upper valve and a
number of small specimens of the genus Ostrea were collected at Red
Bay, and two small upper valves from the Bell farm, Walton County,
Fla. These are questionably referred to Ostrea haitensis Sowerby but
may prove to be a new species if more and better preserved specimens
are procured from these localities. The larger specimen appears to
be less flattened and has fewer plications than Ostrea haitensis Sow-
erby. Smaller specimens representing the opposite valve have a
roughened surface but no radial plications.
Figured specimen (Cat. No. 371132, U. S. N. M.).
Occurrence: Upper middle Miocene: Arca zone-Red Bay, Walton
County; station 12044, Bell farm, upper locality, Walton County.
Yoldia zone provisionally, station 12718, upper bed at Chester Spence
farm, Walton County.


asDall, W. H, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 679, 1898.






56 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Ostrea sculpturata Conrad
Plate 8, Figures 2, 3
1832. Ostrea virginiana var., Conrad, Fossil shells of the Tertiary formations of
North America, p. 28, pl. 14, fig. 2.
1840. Ostrea sculpturata Conrad, Fossils of the medial Tertiary of the United States,
p. 50, pl. 25, fig. 3.
1840. Ostrea subfalcata Conrad, idem, fig. 2.
1855. Ostrea virginiana Tuomey and Holmes (not Gmelin), Pleiocene fossils of
South Carolina, p. 20, pl. 5, figs. 7-9 (fig. 6 excluded).
1875. Ostrea perlirata Conrad. Kerr, North Carolina Geol. Survey Rept., Appen.
dix, p. 18.
1887. Ostrea meridionalis Heilprin, Wagner Free Inst. Sci. Trans., voL 1, p. 100,
pl. 14, figs. 35, 35a.
1898. Ostrea sculpturata Conrad. Dall, Wagner Free Inst. Sci. Trans., vol. 3,
pt. 4, p. 686.
1919. Ostrea sculpturata Conrad. Gardner and Aldrich, Acad. Nat. Sci. Philadel-
phia Proc., vol. 71, p. 18 (in list).
Conrad described this species in 1840 as follows:
Shell subovate, plicated, folds very irregular, superior valve flat; disks with
short irregular impressed lines; cardinal area large; cartilage groove oblique, not
deeply impressed; muscular impression very long and obliquely sublunate. James
River, near Smithfield, Va.
Occurrence: Upper Miocene: Ecphora zone-station 3423, lower
upper Miocene bed tat Jackson Bluff, Leon County. Cancellaria
zone--station 3421,, Harveys Creek, half a mile above abandoned mill,
Leon County; borrow pit near Jackson Bluff; station 3671, 2 miles
north of Hosford, Liberty County; station 3672, 234 miles northwest
of Hosford; station 1/422;,Hanlin Pond, Washington County; station
1/706, Gully Pond, Washington County; station 1/953, 1 mile below
Econfina bridge, Bay County.'
"; 'Outside boc~urtnce:'Mieente': Yorktown formation, Virginia and
North Carolina'; Duplin marl, Carolinas. Pliocene: Waccamaw marl,
North and South Caroliha; Caloosahatchee marl, Florida.

:r .,-;.. ,: :Superfamily PECTINACEA
:.., .. Family PECTINIDAE
Genus PECTEN Miiller, 1776
~-w- n'ensA bi PECTEN
Si:.I P6ecten (ecteriY ochlockfoneeiisis Mansfield, n. sp.
Plate' 13, 'Figures 1, 3
," r .., I Iu trr, -
Shell of moderate size, equilateral, sculptured with rather strong
i16s. Right valve moderately convex aid evenly rounding to sub-
margins, with 22 to 23 moderately wide, nearly flat, dichotomous ribs
separated by narrower interspaces, thl three'lateral ribs being a little
weaker. Left valve with raised lateral margins, weakly depressed
behind the umbo and nearly flat below, and with 16 slightly rounded
nondichotomous ribs with much widerr interspaces. Ears on right
valve subequal, large, the anterior marked with four radials and the
posterior with the same number of weaker radials. Ears on left






CHOCTAWHATCHEE PELECYPODS


valve concave and marked with one radial situated near .the hinge
line on anterior ear and two on posterior ear. Surface of both valves
covered with moderately coarse concentric lamellae.
Holotype, right valve (Cat. No. 371134, U. S. N. M.), measures:
Length, 96 mm.; height, 84 mm.; diameter, 15 mm. Paratype, left
valve (Cat. No. 371135, U. S. N. M.), measures: Length, 68 mm.;
diameter, 62 mm.
Type locality: Holotype collected from station 3423, lower upper
Miocene bed at Jackson Bluff, Leon County; paratype collected from
Same locality as holotype but was obtained by the Florida Geological
Survey from excavation for concrete mixer.
Pecten raveneli Dall, a species described from the Caloosahatchee
marl of Florida, when compared with the new species, has a smaller
shell, a more convex right valve with more closely spaced ribs, a more
depressed left valve with more numerous and more closely spaced
Sribs, and is marked with much coarser radials on the ears.
Pecten hemicyclicus (Ravenel) has a larger, heavier shell, more
expanded and inflated right valve, and more depressed left valve.
Occurrence: Upper Miocene: Ecphora zone, type locality. Cancel-
laria zone-station 7474, Rock Creek, south of Knox Still Landing,
Franklin County; station 1/422, Hamlin Pond, Washington County
(fragments, identification uncertain).
Pecten (Pecten) macdonaldi Olsson
Plate 14, Figures 5, 6
1922. Pecten macdonaldi Olsson, Bull. Am. Paleontology, vol. 9, p. 370, pl. 19,
figs. 1, 2.
The type of Pecten macdonaldi came from the Toro limestone,
Which caps the hills just west of the locks at Gatun, Panama. The
Toro limestone has been referred to the Pliocene and questionably
to the upper Miocene.
Two moderately sized valves-one representing a right valve and
. the other a left valve-and a number of smaller valves, which were
collected in the vicinity of Red Bay, Walton County, Fla., appear in
all features discernible to be Pecten macdonaldi Olsson. The right
valve from Red Bay, with missing ears, is weakly convex, has 22 mod-
erately wide, low ribs which are wider over the middle of the disk
and narrower above the submargins. Interspaces are narrower than
. the ribs. The left valve is nearly flat between the weakly raised lateral
margins, and has 17 distinct, narrow, moderately high, and squarish
ribs. This form may be an intermediate form between P. gatunensis
Toula and P. macdonaldi Olsson, but in general aspect, though a
smaller shell, it more closely resembles the latter, to which I have
assigned it.





58 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

P. ochlockoneensis n. sp. has a more inflated right valve and more
widely separated ribs on the left valve than the Red Bay form.
Occurrence: Upper middle Miocene: Arca zone-Red Bay, Walton
County; station 12046, Vaughan Creek, upper locality, Walton
County (collected by G. M. Ponton and W. C. Mansfield).
The figured right valve, which was collected from Jim Kennedy
Branch, Red Bay, by Dr. Julia Gardner, measures in length, 78 mm.;
height, 71 mm.
Pecten (Pecten) leonensis Mansfield, n. sp.
Plate 9, Figures 2, 3
Shell small, subovate, subequilateral, both valves strongly sculp-
tured. Right valve strongly inflated; left valve nearly flat. Right
valve sculptured with 10 or 11 sharp, triangular, primary ribs inter-
calated with an occasional secondary radial thread. Left valve with
five primary and six secondary ribs, which are similar in outline to
those on the opposite valve. The secondaries alternate in position
with the primaries and are about half their size. Ears subequal and
are ornamented with five moderately strong radials. The right an-
terior ear is strongly sinuate. The surface of the shell is concen-
trically sculptured with coarse scabrous lamellae. Within, the valves
are strongly scalloped, reflecting the wide exterior intercostal spaces.
Cotypes (Cat. No. 371256, U. S. N. M.) measure: Right valve:
Length, 16 mm.; height, 15 mm.; diameter, 4 mm. Left valve: Length,
18 mm.; height, 17 mm.; diameter, 2 mm.
Type locality: Station 3423, lower upper Miocene bed at Jackson
Bluff, Leon County, Fla.
Occurrence: Upper Miocene: Ecphora zone-at type locality
(three right and seven left valves) ; station 4992, 1 miles south of Hol-
land post office, Leon County (two left valves); station 8862, half a
mile northwest of Clarksville, Calhoun County (fragments, identifica-
tion uncertain.)
Outside occurrence: Specimens collected from the upper Miocene
at stations 5241, 5242, highest fossiliferous beds at Porters Landing,
Savannah River, Ga., agree very closely with the Florida specimens,.
differing mainly in having more rounded ribs.
One right valve, probably representing a new species, collected
from the Miocene at Raysors Bridge, Edisto River, S. C., is related to
Pecten leonensis.





CHOCTAWHATCHEE PELECYPODS


Subgenus CHLAMYS Bolten, 1778
Section LYROPECTEN Conrad, 1863
Chlamys (Lyropecten) pontoni Mansfield, n. sp.
Plate 10, Figures 1, 2
1916. Pecten madisonius Say?, Mansfield, U. S. Nat. Mus. Proc., vol. 51, p. 601.
(Listed from Red Bay.)
Shell large, rather strongly inflated, nearly equivalve and nearly
equilateral, the posterior region being slightly more produced. Or-
namented with 11 nearly flat to slightly rounded, widely spaced ribs,
which are strong on the middle of the disk but weaker on the sides.
Interradial spaces and surface of the ribs marked with moderately
coarse radial threads which are more prominent between the ribs
than on the surface of the ribs. Three to five weak radials lie on the
extreme posterior and anterior areas of the disk. Ears partly broken
away. Within, the surface distinctly reflects the strong external
ribbing.
Holotype (Cat. No. 371613, U. S. N. M.) measures: Length, 137
mm.; height, 130 mm.; semidiameter, 20 mm.
Type locality: Station 12047, Vaughan Creek, 112 to 2 miles from
its entrance into Alaqua Creek, Walton County. G. M. Ponton and
W. C. Mansfield, collectors.
Chlamys (Lyropecten) jeffersonius Say differs from the new
species in having fewer, wider, and more equal-sized ribs. The
weaker radials on the anterior and posterior sides of the shell slightly
indicate a relationship with the subgenus Nodipecten.
Occurrence: Upper middle Miocene: Arca zone-station 12047,
type locality (one valve) ; Red Bay, Walton County (rare).
This species is named in honor of Mr. G. M. Ponton, of the Florida
Geological Survey.

Chlamys (Lyropecten) jeffersonius Say
Plate 11, Figure 1
1824. Pecten jeffersonius Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4,
p. 133, pl. 9, fig. 1.
The type of Chlamys jeffersonius Say probably came from Virginia,
instead of Maryland as reported by Say.
Two right valves of Chlamys jeffersonius Say were collected by
the Florida Geological Survey from the upper Miocene (Ecphora
zone) at a dripping spring about three-fourths of a mile north of
Clarksville, Calhoun County, Fla. The larger specimen has seven
wide ribs and the smaller has nine. The surface of the shell is sculp-
tured with moderately fine, crenulated radials. This species differs
from Chlamys pontoni n. sp. in having fewer and more equal-sized
ribs.






60 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The typical form of Chlamys jeffersonius begins in the lowest zone
of the Yorktown formation in Virginia. The shell is very large,
nearly equivalve-the left valve is usually more inflated than the
right-equilateral, with 9 or 10 strong ribs. The anterior ear is a
little larger than the posterior and has a shallow byssal insinuation.
The surface of the shell is covered with moderately fine radial threads.
This form is very rare, if present, in the Duplin marl of the Carolinas.
It has been collected near Raysor Bridge, on the Edisto River, S. C.,
and dredged from the bay in the vicinity of St. Petersburg, Fla. A
varietal form having seven to nine ribs occurs in the highest zone of
the Yorktown formation, as developed in the vicinity of Suffolk, Va.
A form more closely allied to the Suffolk form occurs in the highest
fossiliferous bed exposed in the vicinity of Porters Landing, Ga.

Section PLAGIOCTENIUM Dall, 1898
Chlamys (Plagioctenium) eboreus eboreus Conrad
Plate 12, Figure 11
1833. Pecten eboreus Conrad, Am. Jour. Sci., 1st ser., vol. 23, p. 341.
1840. Pecten eboreus Conrad. Conrad (part), Fossils of the medial Tertiary of the
United States, p. 48, pl. 24, fig. 3. (Specimens from Urbanna, Va., excluded.
PI. 23, fig. 2, may represent P. eboreus urbannaensis Mansfield.)
1898. Pecten eboreus var. eboreus Conrad. DalI, Wagner Free Inst. Sci. Trans.,
vol. 3, pt. 4, p. 750.
1903. Pecten eboreus Conrad. Dall, idem, pt. 6, p. 1597. (In list from upper bed
at Alum Bluff, Fla.)
The type locality of Chlamys eboreus Conrad is Suffolk, Va. In
1898, Dall classified different mutations of P. eboreus and designated
each by a varietal name. The form occurring at Suffolk, Va., he
designated "Pecten eboreus eboreus." The shell of Chlamys eboreus
eboreus is large, inequilateral, the posterior region being more pro-
duced. The left valve is usually more convex than the right. The
ribs, which range from 19 to 27, are nearly flat over the dorsal area
and rounded over the ventral area. Radial threads are usually absent.
The form occurring in the Florida Miocene, which I refer to C.
eboreus eboreus, has about 18 ribs but in other features agrees closely
with the Suffolk form.
Occurrence: Upper Miocene: Ecphora zone-station 1/962, cut in
old road leading to Watsons Landing, Liberty County (rare); station
2210, upper bed at Alum Bluff, Liberty County (rare); station 1/960,
Darlings Slide, Chipola River, Calhoun County (rare); station 8862,
half a mile northeast of Clarksville, Calhoun County; lower upper
Miocene bed at Jackson Bluff (excavation for concrete mixer), Leon
County (common).
Outside occurrence: This subspecies appears to be confined to the
Yorktown formation of Virginia and North Carolina, being more





CHOCTAWHATCHEE PELECYPODS


abundant and characteristic in beds representing the highest part of
the Yorktown formation as developed around Suffolk, Va.

Chlamys (Plagioctenium) eboreus darlingtonensis Dall
Plate 12, Figure 1
1898. Pecten eboreus var. darlingtonensis Dall, Wagner Free Inst. Sci. Trans., vol. 3,
pt. 4, p. 750.
The typical form of this subspecies occurs in the Duplin marl as
developed in the vicinity of Darlington, S. C. This subspecies differs
from Chlamys eboreus eboreus Conrad in having the disk of the
valve radially striate, a feature which is more pronounced on the left
than on the right valve. Chlamys eboreus solarioides Heilprin, a
closely related Pliocene species, has fewer, squarer, and more distinct
ribs, with finer concentric sculpture over the entire shell and coarser
threads between the ribs than Chlamys eboreus darlingtonensis.
Occurrence: Upper Miocene: Cancellaria zone-station 3421, Har-
veys Creek, half a mile above abandoned mill, Leon County (com-
mon); station 1/966, Double Branch, above highway bridge, Leon
County (rare?); station 1/964, highest bed at abandoned mill on
Harveys Creek, Leon County (rare?) ; station 11732, borrow pit near
Jackson Bluff, Leon County (common) ; station 3671, 2 miles north of
Hosford, Liberty County (common); station 3672, 2%3 miles north-
west of Hosford (rare?) ; station 1/957, half a mile east of Evans, Lib-
erty County (rare); station 1/961, near Woods, Liberty County
(common).
The specimens that I have referred to the subspecies darlington-
ensis from the different localities in the upper'Miocene of Florida
show considerable variation. The specimens from the localities near
Hosford are smoother than the typical, whereas the specimens from
Harveys Creek are more typical and indicate a closer relationship to
the Pliocene form than the specimens from Hosford.
In outside localities this subspecies appears to be more character-
istic of the upper Miocene Duplin marl of the Carolinas than C.
eboreus eboreus, although the two forms integrate and are not easily
distinguished.

Chlamys (Plagioctenium) comparilis Tuomey and Holmes
Plate 11, Figures 5, 6
1855. Pecten comparilis Tuomey and Holmes, Pleiocene fossils of South Carolina,
p. 29, pL 11, figs. 6.10.
1898. Pecten eboreus var. comparilis Tuomey and Holmes. Dall, Wagner Free
Inst. Sci. Trans., vol. 3, pt. 4, p. 750.
Tuomey and Holmes described this species in 1855 as follows:
Shell orbicular, convex, somewhat thick, equivalve, with concentric lines of
growth, ears nearly equal; lower valve, buccal ear notched, radiately and coarsely
ribbed, with five to six ribs; anal ear ribs smaller and more numerous; upper valve,
ears with the radiating lines equal; ribs and interstices nearly equal.





62 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The authors also state that this species has 23 ribs and give the
following localities: Darlington; Smith's, Goose Creek (S. C.).
I have not seen the type of this species but have used for com-
parison the illustrations, which are good. Two right valves, identified
as this species by R. P. Whitfield, collected from the Miocene of
South Carolina and deposited in the United States National Museum,
compare with the original illustrations.
Dall placed comparilis as a variety of "Pecten eboreus," but the two
forms are believed to represent distinct species.
The Miocene form, which Dall59 united with Pecten gibbus, is
more closely related to C. comparilis. C. comparilis is more closely
related to C. circularis Sowerby, a west coast species ranging from
Monterey to the Gulf of California and Paita, Peru, than to P. dislo-
catus Conrad, a Recent species of the southern coast of the United
States.
The average number of ribs on each of the valves of the Florida
specimens referred to this species is 23.
The measurements of the figured specimens are: Right valve:
Length, 61 mm.; height, 60 mm.; diameter, 16 mm. Left valve:
Length, 52 mm.; height, 51.5 mm.; diameter, 13 mm.
Occurrence: Upper Miocene: Cancellaria zone-station 3421,
Harveys Creek, half a mile above abandoned mill, Leon County
(abundant); station 1/966, Double Branch, above highway bridge,
Leon County (two valves); borrow pit near Jackson Bluff, Leon
County (common); station 4993, well 1 mile west of Holland post
office, Leon County (rare); 1/953, 1 mile below Econfina bridge, Bay
County (rare) ; station 3671, 2 miles north of Hosford, Liberty County
(one specimen); station 1/706, Gully Pond, Washington County
(common); station 1/422, Hamlin Pond, Washington County (com-
mon) ; station 1/957, half a mile east of Evans, Liberty County (shell
not entire, identification uncertain) ; station 7474, half mile south of
Knox Still Landing, Franklin County.
Outside occurrence: Virginia, Yorktown formation, Petersburg
(one specimen); Nansemond River, 16 miles below Suffolk (one
specimen). The two specimens from Virginia were collected by
Frank Burns. I have not collected this species from Virginia. Geor-
gia, stations 5241 and 6192, upper Miocene at Porters Landing, on the
Savannah River (rare).
Chlamys (Plagioctenium) comparilis jacksonensis Mansfield, n. subsp.
Plate 8, Figures 4, 5
Shell of moderate size, suborbicular in outline, both valves equally
convex, inequilateral-the posterior region being more produced.
59Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 745, 1898.





CHOCTAWHATCHEE PELECYPODS


Right valve sculptured with 21 moderately narrow, elevated ribs sub-
rounded above and nearly flat below and separated by deep inter-
spaces that are a little wider than the ribs. The distal end of each
rib has a raised median thread. Left valve similarly sculptured to
right. Concentric sculpture on the disk of both valves consists of
scaly, rather coarse lamellae. Right and left submargins steeply
inclined and sculptured only with closely set concentric lamellae.
Anterior ear a little longer than posterior, sculptured with four mod-
erately strong radials and transverse lamellae. Surface of posterior
ear marked with about two more radials than anterior. Byssal notch
moderately deep.
Cotypes (Cat. No. 371141, U. S. N. M.) measure: Right valve:
Length, 46 mm.; height, 43 mm.; diameter, 12 mm. Left valve:
Length, 49 mm.; height, 44 mm.; diameter, 13 mm.
The new subspecies differs from C. comparilis in having a pro-
portionately longer shell. It also has about one less rib. The number
of ribs on ten right valves is as follows: One with 23, six with 22, two
with 21, and one with 20; the average number, therefore, is about 22.
The number of ribs on five left valves is as follows: One with 23, two
with 22, two with 21; the average number is about 22. The average
number of ribs on C. comparilis is about 23.
Occurrence: Upper Miocene: Ecphora zone-station 3423, lower
upper Miocene bed at Jackson Bluff, Leon County, Fla., type locality;
Clarksville, Calhoun County. Ecphora or Cancellaria zone-station
1/951, Red Head Still, Washington County (specimens poorly pre-
served, identification uncertain).
Chlamys (Plagioctenium) choctawhatcheensis Mansfield, n. sp.
Plate 9, Figures 4, 8
1916. Pecten gibbus Linnaeus. Mansfield, U. S. Nat. Mus. Proc., vol. 51, p. 601.
(In list.)
Shell rather small, suborbicular, left valve more convex than right,
inequilateral-the anterior region more produced than the posterior.
Right valve sculptured with 21 to 22 broadly rounded to nearly flat
ribs, separated by interspaces that are about half the width of ribs.
Left valve strongly inflated over the middle of the disk, sculptured
with about 21 ribs similar to those on right valve. Submargins with-
out radials. Right ear longer than left; deeply sinuate, and orna-
mented with four rather strong, crenulated radials. Left ear orna-
mented with about two more radials than right.
Cotypes (Cat. No. 371142, U. S. N. M.) measure: Right valve:
Length, 37 mm.; height, 36 mm.; diameter, 8 mm. Left valve:
SLength, 41 mm.; height, 42 mm.; diameter, 14 mm.
This species differs from Chlamys comparilis (Tuomey and






64 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Holmes) in having a more convex left valve and lower, less distinct,
and more closely set ribs. The margin of the ribs on Chlamys com-
parilis projects over the interspaces, whereas in C. choctawhatcheensis
the interspaces are narrow, shallow, and rounded.
The new species is closely related to Chlamys levicostatus Toula
from the Gatun formation of Panama and perhaps should be regarded
as a subspecies of C. levicostatus. C. levicostatus has a smaller shell
with more closely spaced ribs and a more inflated left valve than the
new species.
Occurrence: Upper middle Miocene: Arca zone-vicinity of Red
Bay, Walton County, Fla. (Cotypes from Mr. Anderson's farm, three-
fourths of a mile east of Red Bay) ; station 12046, Vaughan Creek,
upper locality, Walton County; station 12047, Vaughan Creek, lower
locality (specimens small, identification uncertain).
The specimens from station 12046 may be a variety of C. choctaw-
hatcheensis, but they are more closely related to this species than to
Chlamys (Plagioctenium) nicholsi Gardner from its type locality.

Chlamys (Plagioctenium) choctawhatcheensis redbayensis Mansfield, n. subsp.
Plate 11, Figure 3
One left valve from Red Bay is a little different from Chlamys
choctawhatcheensis n. sp. and appears to represent a new subspecies.
It differs from C. choctawhatcheensis in having a less inflated shell
and fewer, more widely spaced, and more distinct ribs. The ribs are
18 in number, moderately wide, and separated by interspaces about
equal in width to ribs. In other features the shell is similar to the
species.
Holotype (Cat. No. 371143, U. S. N. M.) measures: Left valve:
Length, 41 mm.; height, 38 mm.; diameter, 12 mm.
Occurrence: Upper middle Miocene: Arca zone-Jim Kennedy
Branch, about 1 mile east of Red Bay, Walton County, Fla., the type
locality.

Genus AMUSIUM Bolten, 1798
Amusium mortoni (Ravenel)
Plate 11, Figures 2, 4
1844. Pecten mortoni Ravenel, Acad. Nat. Sci. Philadelphia Proc., vol. 2, p. 96.
1855. Pecten mortoni Ravenel. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 27, pl. 9, figs. 1, 2; pL 10, figs. 1, 2.
1858. Pecten mortoni Ravenel. Emmons, North Carolina Geol. Survey Rept., p. 281.
1863. Amusium (Pecten) mortoni Ravenel. Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, p. 582.
1864. Amussium mortoni (Ravenel) Conrad. Meek, Check list of the invertebrate
fossils of North America, Miocene, Smithsonian Misc. Coll., vol. 7, No
183, p. 4.
1898. Pecten (Amusium) mortoni Ravenel. Dall, Wagner Free Inst. Sci. Trans.,
vol. 3, pt. 4, p. 757. (In part.)





CHOCTAWHATCHEE PELECYPODS


Ravenel described this species in 1844 as follows:
Orbicular, thin, both valves moderately convex, one more so than the other-
outside, with numerous concentric obsolete striae; inside, with from 18 to 24
radiating double ribs, slightly elevated; ears large, subequal, striated externally.
Occurrence: Upper Miocene: Ecphora zone-station 2210, upper
bed at Alum Bluff, Liberty County (one valve of young); station
1/962, cut in old road leading to Watsons Landing, Liberty County
(fragments) ; station 3423, lower upper Miocene bed at Jackson Bluff,
Leon County (fragment). Cancellaria zone-station 1/706, Gully
Pond, Washington County (fragments) ; station 3671, 2 miles north of
Hosford, Liberty County (fragment) ; station 7474, Rock Creek near
Knox Still Landing, Franklin County (two fragments); borrow pit,
Jackson Bluff, Leon County (good specimens).
Outside occurrence: Miocene: Yorktown formation, highest zone,
station 2831 (near Suffolk, Va.), station 2835 (Nansemond River, 18
miles below Suffolk, Va.). Duplin marl of the Carolinas. Pliocene:
Florida.
Dallo6 reported this species from Fairhaven and Drum Point, Md.,
by apparently misreading the station numbers. The U. S. Geological
Survey numbers on the specimens are 2831 and 2835. Both specimens
have Cat. No. 146218, U. S. N. M. The localities recorded for these
numbers are Suffolk and 16 miles below Suffolk, Va. However, a few
specimens representing young individuals were collected by the late
Frank Burns, of the United States Geological Survey, from the Calvert
formation at Plum Point, Md., station 3198. These specimens have
faint radials on the ears, a feature which I do not observe on A. mor-
toni, and probably represent another species.

Subgenus PSEUDAMUSSIUM H. and A. Adams, 1858
Pseudamussium sp.
Two specimens, a right and a left valve, collected from the upper
middle Miocene (Arca zone) at station 12046, Vaughan Creek, upper
locality, belong to the genus Pseudamussium. These are related to
P. defuniak Gardner-a species occurring in the highest part of the
Shoal River formation of Florida-but the two are not identical. As
compared with P. defuniak, the right valve of Pseudamussium sp. is
much flatter and the left valve is slightly more inflated. The surface
of the right valve is marked by fine concentric lamellae and obscure
radials, but the surface of the left valve is nearly smooth except for
two or three flat-lying concentric lamellae. P. defuniak has weaker
sculpture over the surface of the shell.
The two specimens may represent a new species, but more material
is desired to substantiate this supposition.
B Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 4, p. 757, 1898.





66 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Family SPONDYLIDAE
Genus PLICATULA Lamarck, 1801
Plicatula marginata Say
Plate 12, Figures 9, 10
1824. Plicatula marginata Say, Acad. Nat. ScL Philadelphia Jour., vol. 4, pp. 136,
137, pl. 9, fig. 4.
1845. Plicaula marginata Say. Conrad, Fossils of the medial Tertiary of the
United States, p. 75, pl. 43, fig. 5.
1845. Plicatula rudis H. C. Lea, Am. Philos. Soc. Trans., n. ser., vol. 9, p. 246,
pl. 35, fig. 34.
1855. Plicatula marginata Say. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 24, pl. 7, figs. 11-14.
1898. Plicatula marginata Say. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 4,
p. 764.
1919. Plicatula marginata Say. Gardner and Aldrich, Acad. Nat. Sci. Philadelphia
Proc., vol. 71, p. 18. (Listed from Muldrow's place, South Carolina.)
Say described this species in 1824 as follows:
Shell ovate-cuneiform, somewhat arcuated at base; with about three much
elevated folds, producing very profound undulations on the edge of the shell; the
intermediate fold is bifid; the whole surface is marked by rather gross concentric
wrinkles; inner margin dusky or blackish, with a series of granules on one valve,
received into corresponding cavities in the opposite valve.
Length one inch and a fifth, breadth one inch.
Plicatula densata Conrad, a species occurring in the Calvert for-
mation of the Chesapeake group of Maryland and New Jersey and in
the Chipola marl and Oak Grove sand of the Alum Bluff group of
Florida, is distinguished from P. marginata Say by its usually rounder
form, more numerous and less prominent plications, heavier shell,
and more prominent muscle scar. Dr. Gardner6s has reported Plica-
tula densata from the St. Marys and Yorktown formations, Virginia
and North Carolina, but I have not recognized it in collections at these
horizons in either State.
Occurrence: Upper Miocene: Ecphora zone-station 2210, upper
bed on Apalachicola River at Alum Bluff, Liberty County, Fla. (one
young specimen); station 1/962, cut in old road to Watsons Landing,
Liberty County (rare); station 3423, Jackson Bluff, lower upper Mio-
cene bed, Leon County (common). Cancellaria zone-station 3421,
Harveys Creek, Leon County, half a mile above abandoned mill
(common); station 1/966, Double Branch, Leon County (rare?);
station 1/706, Gully Pond, Washington County (rare?) ; station 1/422,
Hamlin Pond, Washington County (common); station 8176, "Dead-
ens," Washington County (common); borrow pit, Jackson Bluff, Leon
County (common).
Outside occurrence: Miocene: Yorktown formation, Virginia and
North Carolina; 'Duplin marl, Carolinas. Pliocene: Caloosahatchee
marl, Florida; Waccamaw marl, Carolinas.
The Recent species of the genus Plicatula are more abundant in
the warmer seas, and it is likely that the presence of the genus with a
elGardner, Julia, U. S. Geol. Survey Prof. Paper 142-A, p. 52, 1926.





CHOCTAWHATCHEE PELECYPODS


number of individuals in the fossil state would indicate that the tem-
perature of the water in which it lived was not very cold.
Family LIMIDAE
Genus LIMA (Bruguinre) Cuvier, 1798
Section MANTELLUM Bolten, 1798
Lima (Mantellum) carolinensis Dall
Plate 13, Figure 4
1898. Lima (Mantelum) carolinensis Dall, Wagner Free Inst. ScL Trans., vol. 3,
pt. 4, p. 767, pl. 35, fig. 21.
Dall described this species as follows:
Shell small, thin, inflated, oblique, with moderate gape, sculptured with
concentric lines of.growth and rather sharp, fine, numerous, somewhat irregular
radial threads, obsolete on the beaks, absent from the posterior submargin and
the anterior ears; submargins not impressed, beak prominent, ears small, the margin
of the gape forming a concave sinuosity in front of and below the anterior beak;
hinge line short, with a very wide pit, its lower margin projecting from the car-
dinal plate; interior radially striate, the basal margin slightly crenulate. Alt. 16,
lat. 12, diam. 7 mm.
The type locality of Lima carolinensis is Darlington, S. C. (station
2025). The type (Cat. No. 107801, U. S. N. M.) is deposited in the
United States National Museum.
The Florida Miocene specimens that I have assigned to this species
are much larger than the type specimen or specimens from the Duplin
marl of North Carolina but closely agree in other characters. They
approach in size Lima caloosana Dall, a Pliocene species from the
Caloosahatchee marl of Florida, but differ from that species in having
finer radial threads.
S Occurrence: Upper Miocene: Cancellaria zone-station 3421, Har-
veys Creek, half a mile above abandoned mill, Leon County, Fla. (four
fragments in all, two of which were collected by Dr. T. W. Vaughan
and two by the Florida Geological Survey).
Outside occurrence: Upper Miocene, Duplin marl, Natural Well,
N. C., and Darlington, S. C. Questionably reported from the Oak
Grove sand, of the Alum Bluff group of Florida, by Gardner.62

Superfamily ANOMIACEA
Family ANOMIIDAE
Genus ANOMIA (Linnaeus) Gray, 1847
Anomia simplex D'Orbigny
Plate 13, Figure 2
1845. Anomia simplex D'Orbigny, in De la Sagra, Histoire physique, politique et
naturelle de l'Ile de Cuba, Mollusques de Cuba, vol. 2, p. 367 (1846), pl. 28,
figs. 31-33, (Spanish ed., 1845).
1845. Anomia ephippium var. Conrad, Fossils of the medial Tertiary of the United
States, p. 75, pL 43, fig. 4.
1852. Anomia conradi D'Orbigny, Prodrome de paleontologie statigraphique, vol.
3, p. 134, pl. 25, fig. 30.
1855. Anomia ephippium. Tuomey and Holmes, Pleiocene fossils of South Caro-
lina, p. 18, pl. 5, fig. 4. (Not Linn6.)
e2Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-A, p. 53, 1926.





68 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

1858. Anomia ephippium. Holmes, Post-Pleiocene fossils of South Carolina, p. 11,
pL 2, fig. 11. (Not Linne.)
1858. Anomia ephippium. Emmons, North Carolina Geol. Survey Rept., p. 277.
(Not Linn6.)
1863. Anomia conradi D'Orbigny. Conrad, Acad. Nat. Sci. Philadelphia Proc. for
1862, vol. 14, p. 582.
1864. Anomia conradi D'Orbigny. Meek, Check list of the invertebrate fossils of
North America, Miocene; Smithsonian Misc. Coll., vol. 7, No. 183, p. 4.
1889. Anomia simplex D'Orbigny. Dall, U. S. Nat. Mus. Bull. 37, p. 32, pl. 53,
figs. 1, 2.
1898. Anomia simplex D'Orbigny. Dall, Wagner Free Inst. Sci. Trans., voL 3,
pt. 4, p. 784.
(?)1904. Anomia simplex D'Orbigny. Glenn, Maryland Geol. Survey, Miocene, p.
369, pl. 98, fig. 1.
The shell of this species is of moderate size, semiorbicular in out-
line, thin, and translucent. The upper valve is strongly convex,
whereas the lower valve is irregularly flat. The exterior surface is
commonly smooth, but many specimens are marked with concentric
lines and faint radials.
Occurrence: Upper middle Miocene: Arca zone-Red Bay, Walton
County (worn specimen, identification uncertain). Upper Miocene:
Ecphora zone-station 3423, Jackson Bluff, Ochlockonee River, Leon
County, lower upper Miocene bed (rare). Cancellaria zone-Har-
veys Creek, half a mile above the abandoned mill, Leon County (three
valves collected by Florida Geological Survey) ; station 3422, Jackson
Bluff, upper bed (common); station 1/964, abandoned mill, Harveys
Creek, highest bed (one valve); station 1/961, near Woods, Liberty
County (common).
Outside occurrence: Miocene: ?St. Marys formation, Maryland;
Yorktown formation, highest zone, Virginia; Duplin marl, Carolinas.
Pliocene: Waccamaw marl, Carolinas; Caloosahatchee marl, Florida.
Pleistocene: Atlantic and Gulf coasts. Recent: Cape Sable, Nova
Scotia, to Martinique.
Glenn63 referred a small specimen to A. simplex. Several juvenile
specimens of the genus Anomia, collected by Joseph Willcox on river
banks at St. Marys, St. Marys County, Md. (station 2252), may be
Anomia simplex, but the specimens are too small to determine defi-
nitely. I have not collected this species from the St. Marys formation
of Maryland or Virginia. It is very rare in the latest beds of the
Yorktown formation of Virginia and in the Duplin marl of North
Carolina but much more common in the later Miocene beds of South
Carolina and in the Pliocene beds of the Carolinas and Florida.
Olsson64 reported Anomia simplex from a number of localities in
Panama and Costa Rica. As I have not thoroughly examined speci-
mens from a number of his localities, I am not prepared to express
an opinion.
B3Glenn, L. C., Maryland Geol. Survey, Miocene, p. 369, pl. 98, fig. 1, 1904.
6401sson, A. A., Bull. Am. Paleontology, vol. 9, pp. 381, 382, 1922.





CHOCTAWHATCHEE PELECYPODS


Genus PLACUNANOMIA Broderip, 1832
Placunanomia plicata Tuomey and Holmes
Plate 15, Figures 12, 13, 14
1855. Placunanomia plicata Tuomey and Holmes, Pleiocene fossils of South Caro.
lina, p. 19, pl. 6, figs. 4-6.
1898. Placunanomia plicata Tuomey and Holmes. Dall, Wagner Free Inst. Sci
Trans., vol. 3, pt. 4, p. 778.
1911. Placunanomia plicata Tuomey and Holmes. Vaughan, Georgia Geol. Survey
Bull. 26, p. 368. (Listed from upper horizon at Porters Landing, Ga.)
Tuomey and Holmes described this species in 1855 as follows:
Shell suboval, but variable, subequivalve, subequilateral, slightly foliated, thin,
margin with three or four deep plications; muscular impression large, semi-orbic-
ular, central; upper valve flat near the hinge or beaks; the two ribs in the hinge
slightly divergent.
Locality: Smiths, Goose Creek, S. C.
According to Tuomey and Holmes, a living P. plicata was obtained
from Charleston Harbor, but this record is questioned by Dall.
P. cumingii Broderip, a Recent species of the west coast, ranging
from the Gulf of California to the Gulf of Dulce, Costa Rica, as
pointed out by Dall, much resembles P. plicata, but differs from that
species in having a more deeply plicated and heavier shell and a
cardinal border with stronger rugosities. Nevertheless the two species
are very closely related, indicating that the Recent species descended
from the fossil.
This genus appears to have lived on the Atlantic side of North
America not later than the Pliocene. Two valves belonging to this
genus, collected from the Pliocene of Shell Creek and probably repre-
senting an undescribed new species, are in the United States National
Museum. I have not seen specimens from the Pliocene on the east
coast elsewhere. The genus is living on the Pacific side of America.
Occurrence: Upper Miocene: Ecphora or Cancellaria zone-station
1/951, Red Head Still, Washington County, Fla. (one fragment, identi-
fication uncertain). Cancellaria zone-station 1/946, Harveys Creek,
Leon County, Fla. (four valves, three of which were collected by the
Florida Geological Survey); station 7474, Rock Creek, half a mile
south of Knox Still Landing, New River, Franklin County, Fla. (one
valve); station 1/953, 1 mile below Econfina Bridge, Bay County
(young specimens).
Outside occurrence: Upper Miocene: Duplin marl, Natural Well,
N. C.; Smith's, on Goose Creek, S. C.; upper fossiliferous bed at Porters
Landing, Ga.
Placunanomia plicata floridana Mansfield, n. subsp.
Plate 16, Figures 1, 2, 6, 7
Shell thin, subovate, subequilateral, right valve moderately in-
flated, left valve weakly concave. Sculpture similar on both valves and
consisting of eight to nine roughened radial plications which diminish





70 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

in strength laterally. Umbonal area on right valve flat, steeply in-
clined forward, centrally marked by the byssal scar, bounded by a
low ridge against which the ribs terminate. Faint and short radials
lie below this periphery. Umbonal area on left valve small, weakly
elevated, restricted from ribbed area below, marked with concentric
lines and radial threads which transgress a short distance onto the
ribbed area. Auricular crura rather weak, free and spinose at
extremities, and joined at anterior third of length. Cardinal border
short and moderately rugose. Adductor scar rather large; byssal
scar small.
Holotype with both valves intact (Cat. No. 371149, U. S. N. M.)
measures: Right valve: Length, 55 mm.; height, 63 mm.; convexity,
18 mm. Left valve: Length, 55 mm.; height, 63 mm.
Type locality: Borrow pit, Jackson Bluff, Ochlockonee River, Leon
County, Fla. Collected by the Florida Geological Survey.
The new subspecies differs from P. plicata in having a narrower
shell, a more elevated umbonal area on the left valve, and in being
sculptured with more radial plications.
Occurrence: Upper Miocene: Ecphora zone-type locality; sta-
tion 3423, Jackson Bluff, Ochlockonee River, Leon County, lower
upper Miocene bed (four valves); excavation for concrete mixer at
the preceding locality (one valve, collected by the Florida Geological
Survey); Clarksville, Calhoun County (five valves, collected by the
Florida Geological Survey).
Superfamily MYTILACEA
Family MYTILIDAE
Genus MYTILUS Linnaeus. 1758
Mytilus conradianus D'Orbigny?
Plate 13, Figure 7
Two specimens, a right and a left valve, collected from the upper
Miocene (Cancellaria zone) at station 1/966, Double Branch, a short
distance above the highway bridge on the road to Bloxham, Leon
County, Fla., may belong to Mytilus conradianus D'Orbigny, but the
specimens are too poorly preserved to determine this with assurance.
They most closely resemble specimens from the Duplin marl at the
Natural Well, N. C.
The type locality of M. conradianus, described under a preoccupied
name-M. incrassatus-by Conrad,65 is "Natural Well, Duplin County,
N. C." This species has been. reported to occur in nearly all the
deposits of the Chesapeake group in Maryland and Virginia and in
the Duplin marl of the Carolinas. It probably does not occur in
deposits later than Miocene.
65Conrad, T. A., Am. Jour. Sci., 1st ser., vol. 41, p. 347, 1841.






CHOCTAWHATCHEE PELECYPODS


Genus CRENELLA Brown, 1627
Crenella duplinensis waltoniana Mansfield, n. subsp.
Plate 9, Figures 5, 6, 7
Shell small, rather thin, rounded-ovate in outline, equivalve and
nearly equilateral. Sculpture composed of moderately fine closely
set radials, which are obscure on the umbonal area but distinct dis-
tally. The line of divarication is near the medial line of the disk.
Concentric sculpture of weak lines overruns the radials. The denticles
are rather strongly developed and the ligament scar is deeply im-
pressed.
Cotypes (Cat. No. 371614, U. S. N. M.) measure: Left valve: Length,
2.2 mm.; height, 3 mm. Right valve: Length, 2.2 mm., height, 2.8 mm.
Type locality: Station 12046, Vaughan Creek, about 3 miles above
its outlet, Walton County, Fla.
Crenella duplinensis waltoniana is similar in outline to C. duplin-
ensis Dall, a species occurring in the upper Miocene at the Natural
Well, N. C., but differs from that species in having a little heavier
shell which is marked with coarser radials. Crenella divaricata
(D'Orbigny), a species occurring in the Caloosahatchee Pliocene of
Florida and in the Recent fauna from Cape Hatteras to the Barbados,
has a heavier and more elliptical shell than the new subspecies.
Occurrence: Upper middle Miocene: Arca zone-type locality
(abundant); station 12044, Bell farm, upper locality, Walton County
(common); Red Bay, Walton County (common).

Order ANOMALODESMACEA
Superfamily ANATINACEA
Family PERIPLOMATIDAE
Genus PERIPLOMA Schumacher, 1817
Periploma discus Gardner
1926. Periploma discus Gardner, U. S. Geol. Survey Prof. Paper 142-A, p. 61, pl. 15,
figs. 11.13.
Periploma discus Gardner was described from the Shoal River for-
mation at 6 miles west-northwest of Mossyhead, Walton County, Fla.
Imperfect specimens obtained from the Area zone of the Choctaw-
hatchee formation appear to belong to P. discus Gardner.
Periploma peralta Conrad, a species occurring in the St. Marys
formation of the Chesapeake group of Maryland, is the only species
of the genus so far reported from the Chesapeake group.
Occurrence: Upper middle Miocene: Arca zone-station 12050,
Red Bay, Walton County (rare) ; station 12046, Vaughan Creek, upper
locality, Walton County (rare). Yoldia zone provisionally, station
12718, upper bed at Chester Spence farm, Walton County.






72 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Family THRACIIDAE
Genus THRACIA (Leach MS.) De Blainville, 1824
Thracia conradi Couthouy
Plate 14, Figure 11
1831. Thracia declivis Conrad, American Marine Conchology, p. 44, pl. 9, fig. 2.
(Not Pennant, 1777, British Zoology, vol. 4, p. 79.)
1839. Thracia conradi Couthouy, Boston Jour. Nat. Hist., vol. 2, p. 153, pl. 4, fig. 2.
1841. Thracia conradi Couthouy. Gould, Report on the Invertebrata of Massachu-
setts, p. 50.
1843. Thracia conradi Couthouy. De Kay, Natural History of New York, Zoology,
vol. 1, p. 237, pl. 28, fig. 284.
1870. Thracia conradi Couthouy. Gould, Report on the Invertebrata of Massachu-
setts (2d ed., edited by W. C. Binney), p. 69, fig. 384.
1889. Thracia conradi Couthouy. Dall, U. S. Nat. Mus. Bull. 37, p. 64, pl. 69, fig. 9.
1903. Thracia conradi Couthouy. Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6,
p. 1524. (In part.)

Dall66 gave a new varietal name, harrisi, to the form from Mary-
land and Florida (upper bed at Alum Bluff). The holotype of the
variety was not figured, but a poorly preserved specimen collected
from the left bank of the Patuxent River, a quarter of a mile south
of Burch, Md., and deposited in the United States National Museum
under the catalog number 143888, is designated on the label "Type
of variety."
Glenn writes:67
The fossil shell seems usually to be larger than Couthouy's living ones. Al-
though often abundant, all specimens the writer has seen have been more or less
broken and flattened. -Because of this distortion their exact shape is difficult to
determine and the writer prefers to retain until more perfect material is obtainable
the name conradi. When such material is secured it will very probably show the
fossil to be at least varietally different from the living species. In this event Dr.
Dall's proposed varietal name harrisi will apply.

Subsequent to Dr. Glenn's publication better preserved specimens
of this genus were collected from the Calvert formation of Maryland;
all of these agree with the holotype of T. conradi harrisi Dall. These
specimens have a thinner and higher shell than the Recent species,
and I believe the varietal name harrisi should be retained for the form
occurring in the Calvert formation of Maryland but not for the Florida
fossil form.
I can see no difference between the fossil form from Florida, now
under consideration, and the Recent species.
Occurrence: Upper middle Miocene: Area zone-station 12044,
Bell farm, upper locality, Walton County; station 12045, Bell farm,
lower locality; station 12046, Vaughan Creek, upper locality, Walton
County; station 12267, Taylor Branch on Bryant Scott's farm, Bay
County. Upper Miocene: Ecphora zone-upper bed at Alum Bluff,
Liberty County (fragments).
66Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1525, 1903.
67Glenn, L. C., Maryland Geol. Survey, Miocene, pp. 360, 361, 1904.






CHOCTAWHATCHEE PELECYPODS


Outside occurrence: Upper Miocene: Yorktown formation (lower
part), station 1/211, bank of Blackwater River, half a mile above
Zuni, Isle of Wight County, Va. Recent, Labrador to Hatteras.68

Family PANDORIDAE
Genus PANDORA Hwass, 1795
Subgenus CLIDIOPHORA Carpenter, 1861
Pandora (Clidiophora) crassidens Conrad
Plate 12, Figures 4, 7
1838. Pandora crassidens Conrad, Fossils of the medial Tertiary of the United
States, p. 2, pl. 1, fig. 2.
1863. Pandora crassidens Conrad. Conrad, Acad. Nat. Sci. Philadelphia Proc. for
1862, vol. 14, p. 572.
1864. Pandora crassidens Conrad. Meek, Check list of the invertebrate fossils of
North America, Miocene; Smithsonian Misc. Coll., vol. 7, No. 183, p. 12.
1903. Pandora (Clidiophora) crassidens Conrad. Dall, Wagner Free Inst. Sci.
Trans., voL 3, pt. 6, p. 1519. (In part.)
Conrad described this species in 1838 as follows:
Shell perlaceous, concentrically wrinkled; the large valve extending much
beyond the posterior base of the lesser; anterior side very short, margin widely
subtruncate; posterior obtusely rounded inferiorly, terminating above in a very
short and obtuse rostrum; dorsal submargin of the larger valve with two approx-
imate carinae; lesser valve with only one distinct carina placed very near the
margin; anterior cardinal tooth of the larger valve very long, thick, and slightly
oblique, the posterior one very near the dorsal line, sulcate or fosset shaped; the
middle one short and linear; in the flat valve, two oblique, very thick and prom-
inent teeth, anterior to which is a shallow groove, bounded anteriorly by a rudi-
mentary linear tooth; muscular impressions impressed; pallial impression punctate.
Locality: James River, near Smithfield, Va.
The shell of this species is large and thick, with strong teeth. The
right valve (flat valve) is radially striated.
Pandora (Clidiophora) tuomeyi Gardner and Aldrich, though
similar in dentation to P. crassidens, has a thinner, smaller, and pro-
portionately more elongate shell and appears to be a more charac-
teristic form in the Miocene Duplin marl and in the Pliocene.
P. crassidens, as pointed out by Dall, is a precursor of the Recent -
species, P. gouldiana Dall, which ranges from Prince Edward Island
to Cape May, N. J.
Occurrence: Upper Miocene: Ecphora zone-station 2210, upper
bed at Alum Bluff, Liberty County (quite rare); station 1/962, cut
in old road to Watsons Landing, Liberty County (rare) ; station 8862,
near Clarksville, Calhoun County (one fragment).
Outside occurrence: Upper Miocene: Yorktown formation, Vir-
ginia and North Carolina. More common in zone 2, where in some
beds it attained a large size, as in the Yoldia-bearing bed above York-
town, Va.


68Dall, W. H., U. S. Nat. Mus. Bull. 37, p. 64, 1889.





74 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Subgenus KENNERLEYIA Carpenter, 1864
Pandora (Kennerleyia) arenosa Conrad
Plate 12, Figures 2, 3
1834. Pandora arenosa Conrad, Acad. Nat. Sci. Philadelphia Jour., vol. 7, p. 130.
1838. Pandora arenosa Conrad. Conrad, Fossils of the medial Tertiary of the
United States, p. 2, pl. 1, fig. 3.
1848. Myodora arenosa (Conrad). Conrad, Acad. Nat. Sci. Philadelphia Proc. for
1846, vol. 3, p. 21.
1863. Pandorela (Pandora) arenosa (Conrad). Conrad, Acad. Nat. Sci. Philadel-
phia Proc. for 1862, vol. 14, p. 572.
1864. Pandorella arenosa (Conrad). Meek, Check list of the invertebrate fossils
of North America, Miocene: Smithsonian Misc. CoIL, voL 7, No. 183, p. 12.
1868. Pandora arenosa Conrad. Conrad, Am. Jour. Conchology, vol. 3, p. 269.
1885. Pandora carolinensis Bush, Connecticut Acad. Sci. Trans., vol. 6, pt. 2, p. 474.
1903. Pandora (Kennerleyia) arenosa Conrad. Dall, Wagner Free Inst. Sci. Trans.,
vol. 3, pt. 6, p. 1518.
1919. Pandora (Kennerleyia) arenosa Conrad. Gardner and Aldrich, Acad. Nat.
Sci. Philadelphia Proc, voL 71, p. 18. (In list with fauna from locality
near Mayesville, S. C.)
Conrad described this species in 1834 as follows:
Shell elliptical; obtusely pointed behind; dorsal margin rectilinear, with a
submarginal raised line passing from the beak to the extremity; anterior side short,
margin rounded. Length two-thirds of an inch.
Locality: Yorktown, Va.
The shell of this species is small, with a strongly convex left valve
and a weakly depressed and radially striated right valve. I see no
character by which this species can be separated from P. carolinensis
Bush. The species is living in large numbers off Cape Hatteras at
depths ranging from 7 to 48 fathoms and in temperature ranging
from 58* to 78.
The depths from 15 to 17 fathoms and temperature around 72
appear to be more favorable to its existence.
Occurrence: Upper middle Miocene: Area zone-station 12046,
Vaughan Creek, upper locality, Walton County (common). Upper
Miocene: Ecphora zone-station 1/956, upper bed at Alum Bluff, Lib-
erty County (one small valve). Cancellaria zone-station 1/422,
Hamlin Pond, Washington County (two valves); station 11732, borrow
pit near Jackson Bluff, Leon County (common).
Outside occurrence: Upper Miocene: Yorktown formation, zone
2 and higher, Virginia and North Carolina (rare) ; Duplin marl, Caro-
linas (more abundant in South Carolina). Pliocene, Shell Creek, Fla.

Pandora (Kennerleyia) sp.
A number of fragments of the genus Pandora have been collected
from the upper Miocene (Cancellaria zone) near Hosford, Fla. (sta-
tions 3671, 3672), which may represent a new species, but the material
at hand is inadequate to determine this definitely. The form is re-
lated to P. arenosa Conrad but differs from that species in having a
larger shell, with a less inflated left valve and stronger teeth. The






CHOCTAWHATCHEE PELECYPODS


anterior cardinal is short and the middle cardinal weakly developed.
Fragments of the right valve reveal a radiating sculpture.
Subfamily POROMYACEA
Family CUSPIDARIIDAE
Genus CUSPIDARIA Nardo, 1840
Subgenus CARDIOMYA A. Adams, 1864
Cuspidaria (Cardiomya) ornatissima (D'Orbigny) Dall
Plate 12, Figure 8
1845. Sphena ornatissima D'Orbigny, in De la Sagra, Histoire physique, politique et
naturelle de l'ile de Cuba, Mollusques de Cuba, vol. 2, p. 286, 1846; atlas,
pl. 27, figs. 13-16, 1845.
1885. Neaera costata Bush, Connecticut Acad. Arts and Sci. Trans., vol. 6, p. 472,
pl. 45, fig. 21; U. S. Com. Fish and Fisheries Rept. for 1883, p. 587, 1885.
(Not Sowerby, 1834.)
1886. Cuspidaria (Cardiomya) ornatissima D'Orbigny. Dall, Harvard College Mus.
Comp. Zoology Bull., vol. 12, p. 296.
1889. Cuspidaria (Cardiomya) ornatissima D'Orbigny. Dall, U. S. Nat. Mus. Bull.
37, p. 66, No. 420, pi. 41, fig. 21.
1898. Cardiomya glypta Bush, U. S. Nat. Mus. Proc., vol. 20, p. 810, pl. 71, fig. 1,
pl. 76, figs. 3, 7.
1903. Cuspidaria (Cardiomya) ornatissima D'Orbigny. Dall, Wagner Free Inst.
Sci. Trans., vol. 3, pt. 6, pp. 1506, 1507.
Concerning this species Dall69 writes:
Pliocene marls of the Caloosahatchee and Shell Creek, Fla., Dall and Burns;
living from Cape Hatteras, N. C., southward to Cuba and Guadeloupe in 2 to 124
fathoms.
This is the most abundant species of our recent fauna and very variable as
regards the radial sculpture and to some extent also varying in convexity and form.
The major radials are crenulate and slightly flattened above; finer radial threads
may appear in the interspaces and sometimes nearly reach the strength of the
others; there are usually five to eight major radials, the minor ones may be few
or reach ten or twelve in number; the rostrum may have two or three faint threads
or be almost smooth. Orbigny's figures are taken from half-grown specimens, yet
one is figured as having eight ribs on one valve and thirteen on the other in the
same individual. No characters having been indicated by which they can be con-
stantly differentiated, I have no hesitation in uniting Miss Bush's species with that
of Orbigny.
Occurrence: Upper Miocene: Cancellaria zone-the borrow pit,
Jackson Bluff, Leon County, Fla. (one right valve collected by the
Florida Geol. Survey).
Outside occurrence: Pliocene, Caloosahatchee marl, Caloosa-
hatchee River and Shell Creek, Fla. Living from Cape Hatteras, N. C.,
southward to Cuba and Guadeloupe, in 2 to 124 fathoms.
One specimen, a right valve, collected from the Duplin marl near
Mayesville, S. C. (station 4000), is in the collection of the United States
National Museum and may represent a varietal form of C. ornatissima.
The specimen is similarly sculptured but is more compressed.
Cuspidaria (Cardiomya) ornatissima vaughani Mansfield, n. subsp.
Plate 12, Figures 5, 6
One specimen, a left valve, collected by Dr. T. W. Vaughan at a
locality 23/4 miles northwest of Hosford, Liberty County, Fla. (station
69Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1507, 1903.





76 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

3672), agrees in all features discernible with C. ornatissima D'Orbigny
except in the nature of the external sculpture. The sculpture on the
disk consists of eight major radials, which gradually weaken anteri-
orly, and a minor radial intercalating the major radials. Eight radial
threads ornament the rostral area, five of which lie on its ventral slope,
one at the crest, and two on the dorsal slope. On all specimens that I
have seen of C. ornatissima there are no radial threads'on the ventral
slope of the rostrum.
Holotype (Cat. No. 371154, U. S. N. M.), left valve measures:
Length, 8 mm.; height, 5 mm.; diameter, 1.6 mm.
Occurrence: Upper Miocene: Cancellaria zone-station 3672, 2%3
miles northwest of Hosford, Liberty County.
Order TELEODESMACEA
Superfamily ASTARTACEA
Family ASTARTIDAE
Genus ASTARTE Sowerby, 1818
Section ASHTAROTHA Dall, 1903
Astarte (Ashtarotha) floridana Dall
Plate 14, Figures 9, 10
1903. Astarte (distans var.?) floridana Dall, Wagner Free Inst. Sci. Trans., vol. 3,
pt. 6, p. 1493, pl. 57, fig. 19.
Dall describes this species as follows:
Shell subtriangular with acute, slightly prosogyrate beaks, compressed, subros-
trate, with a few wide ripples near the umbones, the ventral half of the disk, or
more, smooth; lunule and escutcheon narrow, elongate, smooth, the former deeply
excavated. Height 23, length 25, diameter 9 mm.
This shell recalls undulata but has not the high, gibbous beaks and is a smaller
and flatter species; it differs from distans by its thick and heavy hinge, like that of
undulata, its thicker shell, and more rostrate valves.
Dall reports this species from Alum Bluff [upper bed], Liberty
County, and from Bailey, Calhoun County, Fla. The figured type
came from a well at Bailey post office, about 5 miles below Baileys
Ferry (station 3418). Astarte distans Conrad has a more ovate,
thinner, and less posteriorly produced shell than A. floridana.
Occurrence: Upper Miocene: Ecphora zone-type locality; upper
bed at Alum Bluff, Liberty County (rare) ; station 8862, near Clarks-
ville, Calhoun County (common) ; station 3423, lower upper Miocene.
bed at Jackson Bluff, Leon County (abundant); station 1/962, cut
in old road leading to Watsons Landing, Liberty County (rare).
Outside occurrence: Station 3991, 1 mile below Raysors bridge,
Edisto River, S. C. Frank Burns, collector, 1904.
Astarte (Ashtarotha) floridana leonensis Mansfield, n. subsp.
Plate 14, Figures 7, 8
Shell mainly similar to Astarte floridana Dall but differs in being
smaller, proportionately more elongate, and in having shorter and
less prosogyrate beaks and a less strongly developed hinge. The






CHOCTAWHATCHEE PELECYPODS


ventral margin near the posterior extremity is also more incurved.
SThe sculpture consists of five or six moderately small, rounded con-
centric lines on the beaks and strong undulations on the upper part
of the disk only.
Holotype (Cat. No. 371156, U. S. N. M.) measures: Left valve:
Length, 23 mm.; height, 18 mm.; diameter, 4 mm.
Type locality: Station 3421, Harveys Creek, half a mile above the
Abandoned mill, Leon County, Fla.
Occurrence: Upper Miocene: Cancellaria zone-*-type locality
(rare) ; station 1/706, Gully Pond, Washington County (rare) ; station
1/422, Hamlin Pond, Washington County (rare); station 1/961, near
SWoods, Liberty County (fragment, identification uncertain) ; borrow
I pit, Jackson Bluff, Leon County (one immature specimen; identifica-
tion uncertain).
Outside occurrence: A few small specimens from station 5241,
upper Miocene bed at Porters Landing, Savannah River, Ga., may
belong to the new subspecies.

Astarte (Ashtarotha) vaughani Mansfield
Plate 13, Figures 5, 6
1916. Astarte (Ashtarotha) vaughani Mansfield, U. S. Nat. Mus. Proc., vol. 51, p.
605, pl. 113, figs. 8, 9.
The shell of this species is small, subtriangular, and nearly equi-
lateral; basal margin rounded; beaks acute but not extensively pro-
duced; sculptured only on upper third of disk by broadly rounded
undulations.
Astarte (Ashtarotha) sima Gardner, a species confined to the Shoal
River formation of Florida, somewhat resembles A. vaughani, but the
former species has a larger and more inequilateral shell with a less
rounded base and a stronger and more extended beak. Astarte glenni
Dall, a species occurring in the Duplin marl of South Carolina, has a
more inequilateral shell and more drawn-out beaks than A. vaughani
Sand also lacks the undulating sculpture.
Occurrence: Upper middle Miocene: Arca zone-type locality,
Red Bay, Walton County, Fla. Upper Miocene: Ecphora zone-Per-
menter's old place, Walton County (specimens larger than typical).

Astarte (Ashtarotha) glenni jacksonensis Mansfield, n. subsp.
Plate 14, Figures 1, 2
Shell similar to Astarte glenni Dall in general features but differs
in being smaller and in having more pronounced concentric sculpture.
Shell subtriangular, oblique, the posterior region being more ex-
tended. The sculpture consists of moderately fine ripples on the
beaks and broad undulations on the disk, the strength of these grad-






78 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

ually increasing ventrally. Both valves are similarly sculptured.
Astarte glenni is smooth except for a few weak ripples on the beak.
Cotypes (Cat. No. 371157, U. S. N. M.) measure: Right valve:
Length, 8 mm.; height, 8 mm.; diameter, 1.8 mm. Left valve: Length,
8 mm.; height, 8 mm.; diameter, 1.7 mm.
Type locality: Station 3423, lower upper Miocene bed at Jackson
Bluff, Leon County, Fla. Dr. T. W. Vaughan, collector.
Occurrence: Upper Miocene, Ecphora zone-known only from the
type locality.
Astarte sp., aff. A. symmetrica Conrad
Plate 14, Figure 3
A number of small specimens belonging to the genus Astarte, col-
lected from the lower upper Miocene bed (Ecphora zone) at Jackson
Bluff, Leon County, Fla., by Dr. T. W. Vaughan, appear to be closely
related to A. symmetrica Conrad.
The specimens are subovate in form, thick, and have a relatively
high spire. The sculpture consists of elevated, uniformly placed,
strong concentric ribs resembling those on some species of the genus
Chione.
The type locality of A. symmetrica was given as Yorktown, Va., by
Conrad. According to my observations, this species occurs in beds
directly underlying the fragmental series at Yorktown, Va., and else-
where, or in the lower part of zone 2 of the Yorktown formation. It
is closely related to A. coheni Conrad, a species confined to the York-
town formation and most commonly occurring in the fragmental
series.
The dimensions of the figured Florida specimen are: Length, 5.5
mm.; height, 5 mm.; diameter (one valve), 2 mm. Some specimens
are a little larger than the one figured.

Family CRASSATELLITIDAE
Genus CRASSATELLITES Kriiger, 1823
Section CRASSATELLITES
Crassatellites (Crassatellites) meridionalis Dall
Plate 17, Figures 7a, 7b
1900. Crassatellites (Scambula) melinus Conrad var. meridionalis Dall, Wagner
Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1473, 1903 (described) ; pt. 5, pl. 37,
figs. 6, 13, 1900.
1929. Crassatellites meridionalis Dall. Cooke and Mossom, Florida Geol. Survey
Twentieth Ann. Rept., pl. 17, fig. 7.
The shell of this species is rather large, moderately inflated, sub-
ovate in outline, and subequilateral, the posterior region being longer
than the anterior. The posterior region is rather sharply attenuated,
whereas the anterior region is more rounded. The valves are weakly
depressed in front of and behind the posterior dorsal ridge. Nepionic





CHOCTAWHATCHEE PELECYPODS


undulations extend radially from the apices a distance of 11 to 15 mm.
Holotype, figured by Dall (Cat. No. 114829, U. S. N. M.), measures:
Length, 57 mm.; altitude, 40 mm.; diameter (both valves), 20 mm.
In 1929 I70 raised Dall's variety meridionalis to specific rank.
Occurrence: Upper Miocene: Ecphora zone-station 2210, type
locality, upper bed at Alum Bluff, Liberty County (common); station
3423, lower upper Miocene bed at Jackson Bluff, Leon County (com-
mon); station 8862, near Clarksville, Calhoun County (common);
station 4993, 1 mile west of Holland post office (well), Leon County
(rare); station 1/962, cut in old road to Watsons Landing, Liberty
County (common); station 1/965, lower upper Miocene bed at
abandoned mill, Harveys Creek, Leon County (common); station
3418, well at Bailey post office, Calhoun County (rare).
As the Crassatellites in this paper appear to be more closely re-
lated to Crassatellites sinuatus Kriiger, an Eocene species from the
Paris Basin, than to Scambula perplana Conrad, a peculiar Upper
Cretaceous species, I have provisionally placed them in the section of
Crassatellites.

Crassatellites (Crassatellites) meridionalis rubisiniana Mansfield, n. subsp.
Plate 18, Figures 1, 3, 7
1916. Crassatellites melinus Mansfield, U. S. Nat. Mus. Proc., vol. 51, pp. 601, 602.
(Not Conrad.)
The new subspecies agrees with Crassatellites meridionalis Dall in
all features discernible except in the extent of the nepionic undula-
tions. On C. meridionalis these undulations extend radially from the
apices a distance of 11 to 15 mm., whereas on the new subspecies they
extend, on an average, only about 8 mm.
The adult shell is rather heavy and is provided with a strong and
heavy hinge. The body of the shell is roughened by concentric growth
structures.
Cotypes (Cat. No. 166891, U. S. N. M.) measure: Right valve:
Length, 65 mm.; height, 47 mm.; diameter, 14 mm. Left valve:
Length, 69 mm.; height, 50 mm.; diameter, 13 mm.
Type locality: Red Bay, Walton County, Fla.
Crassatellites meridionalis zrrbannaensis Mansfield and Crassatel-
lites meridionalis surryensis Mansfield, subspecies that occur in the
upper part of the St. Marys formation of Virginia, are closely related
to the Red Bay form, differing mainly in having larger shells which
are less depressed in front of the posterior dorsal ridge.
Occurrence: Upper, middle Miocene: Arca zone-type locality,
Red Bay, Walton County; station 12044, Bell farm, upper locality,
Walton County (common) ; station 12045, Bell farm, lower locality
S 70Mansfield, W. C., U. S. Nat. Mus. Proc., vol. 74, art. 14, pp. 8, 9, 1929.






80 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

(common); station 12046, Vaughan Creek, upper locality, Walton
County (abundant); station 12047, Vaughan Creek, lower locality
(common). Yoldia zone provisionally, station 12718, Chester Spence
farm, upper bed, Walton County.

Crassatellites (Crassatellites) meridionalis alicensis Mansfield, n. subsp.
Plate 19, Figure 5
No perfect specimen of this form has been collected. It attained a
rather large size, as one specimen with a corroded umbo measures
82 mm. in length and 63 mm. in height. Two other specimens, one of
which is figured, show the character of the sculpture over the umbonal
region. This sculpture consists of coarse concentric undulations
which extend radially from the apices, a distance of about 12 mm.
The beaks are nearly flat and show no tendency to incurve. The new
subspecies appears to be more closely related to C. meridionalis, a
species confined to the Ecphora zone, than to C. meridionalis rubi-
siniana n. subsp., from the Arca zone, but it may be an intermediate
form. It differs from the former in having coarser undulations and
from the latter in having fewer undulations over the umbonal area.
Holotype: Cat. No. 371615, United States National Museum.
Type locality: Alice Creek, Walton County; collected by Mr. G.
M. Ponton.
Occurrence: Upper middle Miocene: Arca zone. Known only
from the type locality.

Crassatellites (Crassatellites) gibbesii (Tuomey and Holmes) Dall
Plate 16, Figure 9
1856. Crassatella gibbesii Tuomey and Holmes, Pleiocene fossils of South Carolina,
p. 74, pl. 20, figs. 9, 10.
1858. Crassatella gibbesii Tuomey and Holmes. Emmons, North Carolina Geol.
Survey Rept., p. 290, fig. 215.
1886. Crassatella floridana Dall, Harvard College Mus. Comp. Zoology Bull., vol.
12, p. 256, pl. 6, fig. 12.
1889. Crassatella floridana Dall. Dall, U. S. Nat. Mus. Bull. 37, p. 48, pl. 6, fig. 12;
pl. 42, fig. 4.
1895. Crassatella gibbesii Tuomey and Holmes, var. Harris, Bull. Am. Paleontology,
vol. 1, pp. 89, 90.
1903. Crassatellites (Scambula) gibbesii (Tuomey and Holmes). Dall, Wagner
Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1474.
Tuomey and Holmes described this species in 1856 as follows:
Shell somewhat triangular, thick, concentrically furrowed; buccal side rounded;
anal side somewhat beaked, angular, with a longitudinal ridge; umbones incurved;
lunule somewhat excavated.
This well-defined species is easily distinguished from any of the varieties of
the preceding species. The umbones are much incurved and more inflated than in
any form of C. undulata. It differs from the Virginia and Maryland species in its
more symmetrical form and greater regularity of the sulci, which mark the entire
surface of the shell. The ridge on the anal side is prominent, and produces an
undulation which extends to the center of the shell.
Tuomey and Holmes record the type of this species from "Wacca-
maw." Most of the specimens from the Florida Miocene are more






CHOCTAWHATCHEE PELECYPODS


elongate than the larger specimen (fig. 9) figured by Tuomey and
Holmes but agree in shape with some of the Recent specimens referred
to this species. The incurved beaks recall Crassatellites densus Dall, a
species occurring, according to Dr. Julia Gardner, in both the Oak
Grove sand and the Shoal River formation, Florida.
Occurrence: Upper Miocene: Ecphora zone-station 3423, lower
upper Miocene bed at Jackson Bluff, Leon County (rare); station
1/954, near Clarksville, Calhoun County (one small specimen). Can-
cellaria zone-station 3422, upper bed at Jackson Bluff (common);
borrow pit near Jackson Bluff (common); station 1/946, Harveys
Creek, half a mile above the abandoned mill, Leon County (one speci-
men) ; also three specimens collected from the last locality by the
Florida Geological Survey.
Occurrence elsewhere: Miocene: Duplin marl, at the Natural Well
and at Wilmington, N. C.; artesian well at Galveston, Tex., at a depth
of 2,158 to 2,920 feet; Raysors bridge, Colleton County, S. C. (two
small specimens). Pliocene: Waccamaw marl, the Carolinas; Caloo-
sahatchee marl, Alligator Creek, Fla. Recent, from the vicinity of
Cape Hatteras, N. C., south to Barbados, at depth of 3 to 100 fathoms.
The average temperature at which nine lots of the Recent shells
were obtained, as recorded with the specimens in the United States
National Museum, is 75.
Crassatellites (Crassatellites) alaquaensis Mansfield, n. sp.
Plate 18, Figures 4, 6
Shell thick, rather large, moderately inflated and inequilateral, the
posterior region being the longer. Valves weakly depressed in front
of the posterior ridge and weakly inflated over the middle of the disk.
Beaks moderately incurved. Nepionic undulations about five in
number, coarse, and radially extend a distance of about 8 mm. from
the apices.
Holotype, right valve, with the lower margin broken away (Cat.
No. 371616, U. S. N. M.) measures: Length, 70 mm.; height, 45 mm.
Paratype (immature specimen, Cat. No. 371617, U. S. N. M) measures:
Length, 20mm.; height, 12 mm.
Type locality: Permenter's old place, Alaqua Creek, Walton
County. Collected by Mr. G. M. Ponton.
The new species appears to be an intermediate form between C.
densus Dall and C. gibbesii (Tuomey and Holmes). C. densus has a
smaller and more strongly inflated shell, beaks more incurved, and
finer undulations over the beak. The young shell of C. densus is also
relatively shorter than in the new species. C. gibbesii has concentric
sculpture displayed over the whole shell, whereas the new species is
nearly smooth over the middle of the disk.







82 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Occurrence: Upper Miocene: Ecphora zone. Known only from
the type locality.
Genus CRASSINELLA Guppy, 1874
Crassinella lunulata (Conrad)
Plate 15, Figure 6
1834. Astarte lunulata Conrad, Acad. Nat. Sci. Philadelphia Jour., vol. 7, p. 133.
1840. Astarte lunulata Conrad. Conrad, Fossils of the medial Tertiary of the
United States, p. 44, pl. 21, fig. 8.
1856. Astarte lunulata Conrad. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 72, pl. 20, fig. 4.
1863. Gouldia (Astarte) lunulata Conrad. Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, p. 578.
1864. Gouldia lunulata Conrad. Meek, Check list of invertebrate fossils of North
America, Miocene: Smithsonian Misc. Coll., vol. 7, No. 183, p. 7.
1903. Crassatellites (Crassinella) lunulatus Conrad. Dall, Wagner Free Inst. Sci.
Trans., vol. 3, pt. 6, p. 1477, pl. 49, fig. 15.
1919. Crassatellites (Crassinella) lunulatus Conrad. Gardner and Aldrich, Acad.
Nat. Sci. Philadelphia Proc., vol. 71, p. 19.

Conrad described this species in 1834 as follows:
Shell small, triangular, compressed, with about thirteen acute concentric prom-
inent lines; anterior slope rectilinear, angular at the extremity; basal margin
rounded; beaks central, apex acute; lunule much elongated. Length and height
nearly equal, about one-fourth of an inch.
Locality: Suffolk, Va.
Dall71 in his discussion of "Crassatellites (Crassinella) lunulatus"
writes:
This form is very similar to the recent C. mactracea Linsley from Connecticut,
but the latter may usually be distinguished from it, when in good condition, by the,
fine, almost microscopic, radial striation which covers the shell and which is
absent from the fossil form. C. mactracea has not been seen by me in the fossil
state if this character be required. However, I find southern specimens of the
recent shell otherwise apparently identical are without the radial striation. . As
lunulata is unquestionably the oldest specific name there is no doubt as to what we
shall call the fossil, but the decision as to the recent forms must await better
information.

Some of the Florida Miocene forms show radial striations, as do
the more southern Recent forms. I have not placed C. mactracea in
synonymy with C. lunulatus, although I see no constant differences
by which to separate it from the fossil form.
Occurrence: Upper Miocene: Ecphora zone-station 8862, near
Clarksville, Calhoun County (rare); station 3423, lower upper Mio.
cene bed at Jackson Bluff, Leon County (quite rare). Cancellaria
zone-station 3421, Harveys Creek, half a mile above abandoned mill,
Leon County (quite common); borrow pit, Jackson Bluff, Leon
County (rare); station 1/422, Hamlin Pond, Washington County
(rare); station 1/706, Gully Pond, Washington County (rare).
Occurrence elsewhere: Miocene: Yorktown formation, Virginia
and North Carolina; Duplin marl, the Carolinas. Pliocene: Wacca-
maw marl, the Carolinas; Caloosahatchee marl, Florida.
71Dall, W. H., Wagner Free Inst., Sci. Trans., vol. 3, pt. 6, pp. 1477-1478, 1903.






CHOCTAWHATCHEE PELECYPODS


Crassinella acuta (Dall)
Plate 14, Figure 4
1903. Crassatellites (CrassineUa) acutus Dall, Wagner Free Inst. Sci Trans., vol. 3,
pt. 6, p. 1479, pl. 50, figs. 1, 4.
Dall described this species as follows:
Shell small, solid, with very acute, slightly backwardly deflected beaks and
wide, compressed base; lunule and anterior slope straight, of equal length, the
lunule moderately impressed and smooth; posterior slope longer, somewhat ex-
cavated, the escutcheon well impressed, and in specimens with strong sculpture
the carina bounding the escutcheon is often crenulated by the ends of the con-
centric ribs; sculpture of (about fifteen) medially rather elevated, narrow, even,
regular, rounded ribs with much wider excavated interspaces, the ribs less con-
spicuous near the base and varying somewhat in strength in different individuals;
disk but slightly convex, compressed towards the base, so that a section in profile
would be wedge-shaped; hinge strong, the posterior cardinal in the left valve
prominent but more or less coalescent with the dorsal margin. Height 4.0, breadth
4.3, diameter 1.8 mm.
Pliocene of the Caloosahatchee, Shell Creek, and Alligator Creek, Florida;
Willcox, Burns, and Dall.
Occurrence: Upper Miocene: Cancellaria zone-station 3422, up-
permost bed at Jackson Bluff, Leon County; station 3421, Harveys
Creek, half a mile above abandoned mill, Leon County. Rare at both
localities.
Occurrence elsewhere: Pliocene: Caloosahatchee marl, Florida.

Crassinella dupliniana Dall
Plate 15, Figure 9
1903. Crassatellites (Crassinella) duplinianus Dall, Wagner Free Inst. Sci. Trans.,
vol. 3, pt. 6, p. 1478, pl. 50, figs. 5, 6.
1911. Crassinella dupliniana Dall. Vaughan, Georgia Geol. Survey Bull, 26, p. 368.
1919. Crassatellites (Crassinella) duplinianus DalL Gardner and Aldrich, Acad.
Nat. Sci. Philadelphia Proc., vol. 71, p. 19.
Dall described this species in 1903 as follows:
Shell small, subtriangular, solid, with markedly acute beaks, which incline
backward; anterior slope convexly arcuate, long; posterior slope nearly a straight
or slightly concave line, shorter; lunule and escutcheon extending the whole length
of their respective slopes, long and narrow, the latter more excavated than the
former and wider; both are smooth; base arcuate; disk sculptured with rather
close-set, regular, subequal, flattish, concentric ridges with narrower interspaces;
these are sometimes feebly elevated, but preserve their general close-set, regular
character; hinge well developed, the posterior cardinal in the left valve often con-
spicuous. Height 3.2, breadth 3.2, diameter 1.7 mm.
This species is especially characterized by the closeness, regularity, and
smoothness of its concentric ridges and the long and narrow lunule and escutcheon.
Miocene of the Natural Well and Magnolia, Duplin County, N. C., and Pliocene
of Tillys Lake, Waccamaw River, S. C.; Burns and C. W. Johnson.
Occurrence: Upper Miocene: Cancellaria zone-station 3421, Har-
Sveys Creek, half a mile above abandoned mill, Leon County; station
3422, uppermost bed at Jackson Bluff, Leon County; station 1/955,
Gully Pond, Washington County. Rare at all localities.
SOccurrence elsewhere: Upper Miocene: Duplin marl, the Caro-
linas. Pliocene: Waccamaw marl at Tillys Lake, S. C.
I have not found the species in the Yorktown formation in either
Virginia or North Carolina.






84 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Crassinella waltoniana Mansfield, n. sp.
Plate 13, Figures 8, 9, 10
Shell small, ovate, solid, inflated, equivalve, and nearly equilateral.
Beaks not acute, weakly recurved, nearly central. Dorsal margins
nearly equal, the posterior being slightly longer and more direct.
Base well rounded. Lunule and escutcheon impressed, elongate, mod-
erately wide, and nearly of equal length. Sculptured externally at
upper third by rather closely set concentric undulations, the ventral
area being smooth except for weak incremental growth lines.
Cotypes (Cat. No. 371164, U. S. N. M.) measure: Right valve:
Length, 2.3 mm.; height, 2.2 mm. Left valve: Length, 2.3 mm.;
height, 2.2 mm.
Type locality: Station 1/647, 1 mile east of Red Bay, Walton Coun.
ty, Fla.
This species most closely resembles a form referred by Gardner,72
to "Crassatellites (Crassinella) tanicus" Dall, which occurs in the Shoal
River formation of Florida, at station 3748, Somerville mill race, 1
mile east of Argyle, Walton County, but C. waltoniana n. sp. is rela-
tively longer and more convex.
Crassinella dupliniana has a more inequilateral shell, with more
persistent concentric sculpture.
Occurrence: Upper middle Miocene: Arca zone-Red Bay, Walton
County (common) ; station 12046, Vaughan Creek, upper locality,
Walton County (rare).
Superfamily CARDITACEA
Family CARDITIDAE
Genus CARDITA (BruguiBre) Lamarck, 1799
Subgenus CARDITAMERA Conrad, 1838
Cardita (Carditamera) vaughani Dall
Plate 17, Figure 1
1903. Cardita (Carditamera) vaughani Dall, Wagner Free Inst. Sci. Trans., vol. 3,
pt. 6, pp. 1414, 1415, pl. 56, fig. 10.
1929. Cardita (Carditamera) vaughani Dall. Cooke and Mossom, Florida Geol.
Survey Twentieth Ann. Rept., pl. 17. fig. 1.
Dall described this species as follows:
Shell robust, solid, inequilateral, subovate, the beaks low and slightly proso-
gyrate, near the anterior fifth of the valve; lunule narrow, deeply impressed;
sculpture of about fifteen broad, slightly rounded radial ribs separated by channeled
interspaces and crossed by rather thick, elevated threads or elongated nodules,
imbricated toward the beaks and less prominent near the posterior base; the inter-
spaces are only concentrically striated; hinge well developed, the laterals prominent,
the inner margins coarsely fluted. Length 40, height 27. diameter 18 mm.
Miocene of Jackson Bluff and of the Chipola River, 5 miles below the County
bridge, formerly Baileys Ferry; T. W. Vaughan.
The figured type (Cat. No. 164590, U. S. N. M.) came from the
lower upper Miocene bed at Jackson Bluff, Leon County, Fla.
72Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-B, p. 87, 1926.






CHOCTAWHATCHEE PELECYPODS


Occurrence: Upper Miocene: Ecphora zone-station 3423, lower
upper Miocene bed at Jackson Bluff (abundant); station 3418, from
a well at Baileys Ferry on Chipola River, Calhoun County (rare);
station 1/954, near Clarksville, Calhoun County (rare); station 4993,
1 mile west of Holland post office, Leon County (from well; specimens
not entire and identification not confirmed).
This species appears to be confined to the Ecphora zone but is
much more abundant in the upper part of this zone.
Outside occurrence: One imperfect valve, which probably belongs
to Cardita vaughani, was dredged from Tampa Bay, offshore, opposite
the Vinoy Hotel at St. Petersburg, Fla.
Cardita (Carditamera) arata (Conrad)
Plate 15, Figure 1
1832. Cypricardia arata Conrad, Fossil shells of the Tertiary formations of North
America, vol. 1, p. 20, pl. 5, fig. 1.
1838. Carditamera arata (Conrad). Conrad, Fossils of the medial Tertiary of the
United States, p. 11, pl. 6, fig. 2.
The names which Dall7F considered as synonyms of this species have
not been verified by me and consequently are omitted.
Conrad originally described this species as follows:
Oblong, with about 15 profoundly elevated scaly ribs; dorsal and basal mar-
gins parallel; anterior side very short; posterior margin oblique, angular above;
inner margins crenate.
Two valves were collected at the borrow pit near Jackson Bluff,
Leon County, by the Florida Geological Survey, and four valves were
taken from a well near Holland post office, Leon County, station 4993.
*These specimens appear to be the same as C. arata, as illustrated by
Conrad, but may represent a varietal form of his species.
The Florida upper Miocene form has 18 ribs, which are weakly
scabrous over the posterior ridge. This form agrees in outline and
character of ribs with specimens identified as C. arata in the upper
Miocene at the Natural Well, N. C., and also with specimens in the
Caloosahatchee Pliocene of Florida.
Occurrence: Upper Miocene: The specimens from the borrow pit
apparently came from the Cancellaria zone, and those from the well
may have been taken from the Ecphora zone.
Cardita (Carditamera) arata harveyensis Mansfield, n. subsp.
Plate 15, Figures 2, 4, 5
Shell of moderate size, elongate, narrow, rather solid, equivalve,
inequilateral, strongly submedially compressed from beaks to ventral
margins. Umbos low, approximate, tips weakly prosogyrate, situated
at about anterior fifth of shell length. Lunule large, cordate, weakly
depressed, and nearly smooth. Valves strongly arched at the pos-
73Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, pp. 1413-1414, 1903.






86 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

terior keel and moderately inflated at the anterior end. Sculptured
with 15 to 18 high, strong, broadly rounded, and nearly flat radial
ribs, crested by strong concentric annulations. Posterior dorsal mar-
gin nearly parallel to ventral except for the broad mesial constriction
of the ventral margin.
Cotypes (Cat. No. 371165, U. S. N. M.) measure: Right valve:
Length, 35 mm.; height, 19 mm.; diameter, 9 mm. Left valve:
Length, 32 mm.; height, 17 mm.; diameter, 8.5 mm.
Type locality: Harveys Creek, half a mile above abandoned mill,
Leon County, Fla.
This subspecies was assigned to Cardita arata Conrad by Dall,74
but it is a more elongate shell, with the disk more compressed than
the figured type75 of this species.
The new subspecies most closely agrees with specimens from the
Miocene at Darlington, S. G., but it also has a narrower shell than the
Darlington form. The specimens figured by Tuomey and Holmes"
under the name Cardita arata Conrad evidently came from the "Dar-
lington district," as this is the only locality mentioned under that
name. Cardita (Carditamera) defuniak Gardner,77 a species referred
to the Shoal River formation of Florida and apparently confined to
DeFuniak "Cardium beds," appears to be closely related to the new
subspecies, differing mainly in having a lower shell with smoother
and more closely spaced ribs.
Occurrence: Upper middle Miocene: Arca zone-station 12046,
Vaughan Creek, upper locality, Walton County (rare); Red Bay,
Walton County (poor specimen, identification uncertain). Upper
Miocene: Cancellaria zone-station 3421, Harveys Creek, half a mile
above abandoned mill, Leon County (common) ; station 1/966, Double
Branch, just above highway bridge, Leon County (common); station
3671, 2 miles north of Hosford, Liberty County (rare) ; station 1/706,
Gully Pond, Washington County (common); station 1/422, Hamlin
Pond, Washington County (common); station 1/953, 1 mile below
Econfina bridge, Bay County (rare?).
Cardita (Carditamera) defuniak Gardner
Plate 15, Figure 3
1926. Cardita (Carditamera) defuniak Gardner, U. S. Geol. Survey Prof. Paper
142-B, p. 89, pl. 17, fig. 3.
One small specimen collected from the upper middle Miocene
(Arca zone) at station 12044, Bell farm, upper locality, Walton
County, Fla., appears to be C. defuniak Gardner, a species described
74Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1414, 1903.
75Conrad, T. A.. Fossil shells of the Tertiary formations of North America,
vol. 1, pl. 5,fig. 1, 1832.
76Pleiocene fossils from South Carolina, pl. 19, figs. 4, 5, 1856.
77Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-B, p. 89, pl. 17, fig. 3, 1926.






. CHOCTAWHATCHEE PELECYPODS


from the DeFuniak "Cardium beds," Alaqua Creek, Walton County,
and assigned to the Shoal River formation.
The specimen at hand is low and elongate and is sculptured with
18 squarish ribs which are flattened on their summits and separated
by interspaces about equal in width to the ribs. The specimen has
a shorter and lower shell with smoother and more closely spaced ribs
than specimens included under the new subspecies C. arata harvey-
ensis.
Genus VENERICARDIA Lamarck, 1801
Section CYCLOCARDIA Conrad, 1868
Venericardia (Cyclocardia) granulata Say
Plate 15, Figures 10, 11
1824. Venericardia granulata Say, Acad. Nat. Sci. Philadelphia Jour., 1st ser., vol. 4,
p. 142, pl. 12, fig. 1.
1838. Cardita granulata Say. Conrad, Fossils of the medial Tertiary of the United
States, p. 12, pl. 7, fig. 1.
1842. Cardita granulata Say. Conrad, Nat. Inst. for Promotion of Science Proc.,
vol. 2, p. 187.
1856. Cardita granulata Say. Tuomey and Holmes, Pleiocene fossils of South Car-
olina, p. 66, pl. 19, figs. 7, 8.
1858. Cardita tridentata Emmons, North Carolina Geol. Survey Rept., p. 302, fig.
236A. (Not Say, 1826.)
1863. Actinobolus (Cardita) granulata Say. Conrad, Acad. Nat. Sci. Philadelphia
SProc. for 1862, vol. 14, p. 578.
1864. Venericardia (Cardiocardites) granulata Say. Meek, Check list of inverte.
brate fossils of North America, Miocene: Smithsonian Misc. Coll., vol. 7,
No. 183, p. 7.
1889. Venericardia borealis var. granulata Say. Dall, U. S. Nat. Mus. Bull. 37, p. 46.
1894. Cardita granulata Say. Whitfield, U. S. Geol. Survey Mon. 24, p. 56, pl. 9,
figs. 1-4.
1903. Venericardia (Cyclocardia) granulata Say. Dall, Wagner Free Inst. Sci.
Trans., vol. 3, pt. 6, p. 1431.
1904. Venericardih granulata Say. Glenn, Maryland Geol. Survey, Miocene, p. 344,
pl. 91, figs. -7, 8, 9, 10.
1919. Venericardia (Cyclocardia) granulata Say. Gardner and Aldrich, Acad. Nat.
Sci. Philadelphia Proc., vol. 71, p. 19.
Say described this species in 1824 as follows:
Suborbicular, with about twenty-five convex ribs, and wrinkled across; inner
margin crenate.
Beaks nearly central, a little prominent, curved backward; ribs granulated on
the umbones and transversely wrinkled near the base, convex; apices somewhat
prominent beyond the general curve of the shell; inner margin and edge crenate;
cardinal teeth two.
Length from the apex to the base four-fifths of an inch, breadth nearly the same.
Rather proportionally longer than the decussata, and more oblique.
According to Dall78 Venericardia granulata Say is constantly
smaller, more ventricose, and less oblique, with fewer ribs than the
Recent species Venericardia borealis Conrad.
Glenn79 states that none of the Maryland Miocene specimens have
as many as 25 ribs. He gives the number of ribs on specimens from
the three formations in Maryland as follows: Calvert, 18 to 21; Chop-
tank, 16 to 18; St. Marys, 17 to 19. These numbers agree with my
78Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1431, 1903.
79Glenn, L. C., Maryland Geol. Survey, Miocene, p. 345, 1904.





88 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

count. The Calvert specimens have more ribs than the specimens from
the Choptank or St. Marys formation. The individuals are rare in
the St. Marys formation in Maryland but increase in number in the
same formation in Virginia. The specimens from the Yorktown for-
mation of Virginia and North Carolina and from the Duplin marl of
the Carolinas usually have more ribs than specimens from the Calvert,
Choptank, and St. Marys formations, the ribs ranging in number from
about 21 to 26.
The specimens from the upper Miocene of Florida are of moderate
size and have heavy shells with a strong hinge. The ribs are widely
separated and number 16 or 17. The Florida form may represent a
new subspecies, as the number of ribs is about eight fewer than Say
states his species had, and the beaks are more produced and the hinge
heavier than is shown in the illustration of Say's species.
Occurrence: Upper Miocene: Ecphora zone-station 2210, upper
bed at Alum Bluff, Liberty County (rare) ; station 1/962, cut in old
road leading to Watsons Landing, Liberty County (rare) ; station 3418,
5 miles below Baileys Ferry, Calhoun County (abundant); station
8862, near Clarksville, Calhoun County (abundant); station 3423,
lower upper Miocene bed at Jackson Bluff, Leon County (abundant);
station 4993, from well, 1 mile west of Holland post office, Leon County
(rare?). Cancellaria zone-station 3671, 2 miles north of Hosford,
Liberty County (one small valve); station 3421, Harveys Creek, half
a mile above abandoned mill, Leon County (two small valves) ; borrow
pit, Jackson Bluff, Leon County (one small valve).
Occurrence elsewhere: Miocene: Calvert, Choptank, and St. Marys
formations, Maryland and Virginia; Yorktown formation, Virginia
and North Carolina; Duplin marl, the Carolinas. Pliocene, Wacca-
maw marl, the Carolinas.
Subgenus PLEUROMERIS Conrad, 1867
Venericardia (Pleuromeris) perplana var. abbreviata (Conrad)
Plate 16, Figure 5
1841. Cardita abbreviata Conrad, Am. Jour. Sci., 1st ser., vol. 41, p. 347, pl. 2, fig. 17.
I make no attempt to give a synonymy of the variety Venericardia
perplana abbreviata Conrad.
Conrad described this form in 1841 as follows:
Trigonal, elevated, convex-depressed, ribs about eleven, convex, minutely gran-
ulated; posterior extremity angulated.
Conradso listed his new species with those from Wilmington, N. C.
Dall8s placed Cardita abbreviata Conrad in synonymy with V.
perplana Conrad. In commenting upon the variety abbreviata Dall
writes:
soIdem, p. 344.
1sDall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, pp. 1434, 1435, 1903.






CHOCTAWHATCHEE PELECYPODS


This is a ruling form in the older beds but intergrades with typical perplana,
which later gradually supplants it, and so far I have seen no specimens of the
variety among the recent shells.
Venericardia perplana and the variety abbreviata in the fossil
state begin at or about the same time and are found together in the
same deposit.
Occurrence: Upper Miocene: Ecphora zone-station 3423, lower
upper Miocene bed at Jackson Bluff, Leon County (quite common).
Cancellaria zone-station 3421, Harveys Creek, half a mile above
abandoned mill, Leon County (rare) ; station 3672, 2% miles north-
west of Hosford, Liberty County (one valve).
Occurrence elsewhere: Upper Miocene: Yorktown formation, Vir-
ginia and North Carolina, but seldom found below the comminuted
series, the middle part of zone 2 of the Yorktown formation; Duplin
marl, the Carolinas. Pliocene, Waccamaw marl, the Carolinas, and
Caloosahatchee marl, Florida.
The living shells referred to Venericardia perplana range from
Cape Hatteras, N. C., southward to Florida and the Gulf of Mexico.
Venericardia (Pleuromeris) tridentata decemcostata Conrad
Plate 16, Figures 3, 4
1867. Pleuromeris decemcostata Conrad, Am. Jour. Conchology, vol. 3, p. 12.
A full synonymy is not included here. Conrad describes this form
as follows:
Triangular; ribs twelve, rounded ornamented by numerous angular or trans-
verse tubercles over all the ribs.
This shell is nearly related to Say's tridentata but has only twelve ribs, whilst
Say's species has eighteen, and the elevated concentric lines are said to be obsolete
on the anterior side, but in our fossil the tubercles or lines are most prominent
on the anterior side.
Dall82 writes, under the discussion of V. tridentata:
The name was first applied to the Recent form, which does not appear ever to
attain the size and coarseness of sculpture of the fossils, which for this and other
reasons were separated by Conrad in 1867 as a distinct species under the name
decemcostata. I can not satisfy myself that the differences are specific, but if the
fossil be considered a variety it may retain Conrad's name, though the number of
ribs is not constant.
Occurrence: Upper Miocene: Ecphora zone-station 3423, lower
upper Miocene bed at Jackson Bluff, Leon County (common). Can-
cellaria zone-station 3421, Harveys Creek, half a mile above aban-
doned mill, Leon County (common); borrow pit, Jackson Bluff (two
specimens); station 1/953, 1 mile below Econfina bridge, Bay County
(one valve) ; station 3671, 2 miles north of Hosford, Liberty County
(one valve) ; station 3672, 23 miles northwest of Hosford (one valve).
Occurrence elsewhere: Miocene: Duplin marl, the Carolinas.
Pliocene: Caloosahatchee marl, Florida.
82Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1434, 1903.






90 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

The Recent species Venericardia tridentata Say ranges from Cape
Hatteras, N. C., southward to Florida and the Gulf of Mexico.
Venericardia (Pleuromeris) scituloides Olsson
Plate 15, Figures 7, 8
1914. Venericardia (Pleuromeris) scituloides Olsson, Bull. Am. Paleontology, voL 5,
p. 58, pL 8, figs. 3, 4.
Olsson described this species as follows:
Shell small, solid; equilateral, convex triangular in shape; sculpture of 7-9 flat,
broad ribs separated by narrow interspaces; umbones with the ribs coarsely or
evenly granulated or sometimes smooth; on the basal portion, the ribs are crossed
by coarse concentric lines; lunule smooth, very deep, elongated and of a length
roughly onehalf the height of the shell; escutcheon smooth, lanceolate; hinge
rather high and heavy; internal margin fluted by the exterior ribs.
Height 5.50, width 4.75, thickness 5.50 mm.
This species bears much resemblance to V. scitula Dall of the Oligocene of the
Oak Grove sands Florida. The most marked differences are the fewer ribs, those
of V. scitula ranging from 12 to 14 in number and in having these ribs separated by
narrower in-spaces. From V. tridentata Conrad, the species is distinguished by its
fewer ribs and by its shape.
Florida; Miocene of the upper bed at Alum Bluff.
This species is less strongly beaded than Venericardia tridentata
decemcostata Conrad and began at an earlier time in the Floridian
Miocene than the latter species.
Occurrence: Upper Miocene: Ecphora zone-upper bed at Alum
Bluff, Liberty County (quite rare); station 1/962, cut in old road to
Watsons Landing, Liberty County (rare); station 8862, near Clarks-
ville, Calhoun County (common) ; station 3423, lower upper Miocene
bed at Jackson Bluff, Leon County (common); station 4992, well 1
mile southwest of Holland post office, Leon County (one specimen).
Cancellaria zone-station 3672, 23/ miles northwest of Hosford, Lib-
erty County (one eroded specimen; identification uncertain).
Superfamily CHAMACEA
Family CHAMIDAE
Genus CHAMA (Linnaeus), 1758
Chama congregate Conrad
Plate 18, Figures 2, 5
1833. Chama congregate Conrad. Am. Jour. Sci., 1st ser., vol. 23, p. 341.
1838. Chama congregate Conrad. Conrad, Fossils of the medial Tertiary of the
United States, p. 32, pl. 17, fig. 2.
1855. Chama congregate Conrad. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 23, pl. 7, figs. 7-10.
1863. Chama congregate Conrad. Conrad, Acad. Nat. Sci. Philadelphia Proc. for
1862, vol. 14, p. 576.
1894. Chama congregate Conrad. Whitfield, U. S. Geol. Survey Mon. 24, p. 65, pl. 9,
figs. 14-18.
1903. Chama congregate Conrad. Dall, Wagner Free Inst. Sci Trans., vol. 3, pt. 6,
p. 1400.
1904. Chama congregate Conrad. Glenn, Maryland Geol. Survey, Miocene, p. 342,
pl. 91, figs. 1-3.
Conrad described this species in 1833 as follows:
Shell sessile, dextral; superior valve a little convex, with numerous erect ele-
vated arched scales; beaks occasionally rostrated; apex subspiral; scales on the
inferior valve broader and more elevated; inner margin crenulated.
Locality: James River, near Smithfield, Va.





CHOCTAWHATCHEE PELECYPODS


The attached valve is larger and more convex than the free valve.
The sculpture of the attached valve is a little coarser than on the
opposite valve, consisting of imbricated fluted lamellae. The sculp-
ture of the free valve consists of concentric, rather finely fluted, weakly
spinose lamellae.
Occurrence: Upper Miocene: Ecphora zone-station 3418, Bailey
. post office, Calhoun County (one valve); station 1/962, cut in old road
to Watsons Landing, Liberty County (one valve) ; station 8862, near
Clarksville, Calhoun County (abundant); station 3423, lower upper
Miocene bed at Jackson Bluff, Leon County (abundant). Cancellaria
zone-station 1/966, Double Branch, above highway bridge, Leon
County (one specimen); station 3421, Harveys Creek, half a mile
above abandoned mill, Leon County (common); station 8176, "Dead-
ens," Washington County (rare).
Occurrence elsewhere: Miocene: Calvert formation, Maryland; St.
Marys formation, Virginia; Yorktown formation, Virginia and North
Carolina; Duplin marl, Carolinas. Pliocene (?) : the Carolinas. Re-
cent: Cape Hatteras to Brazil.
Although this species has been reported from the Waccamaw marl
of South Carolina, I am not sure that it occurs in these beds. Chama
striata Emmons is a common species in these beds.

Chama striata Emmons
Plate 16, Figures 8, 10
1858. Chama striata Emmons, North Carolina GeoL Survey Rtept., p. 288, fig. 211.
1863. Chama striata Emmons. Conrad, Acad. Nat. Sci Philadelphia Proc. for 1862,
vol. 14, p.'576.
1864. Chama striata Emmons. Meek, Check list of the invertebrate fossils of North
America, Miocene: Smithsonian Misc. Coll, vol. 7, No. 183, p. 8.
1903. Chama striata Emmons. Dall, Wagner Free Inst Sci Trans., vol. 3, pt. 6,
p. 1401.
1919. Chama striata Emmons. Gardner and Aldrich, Acad. Nat. Sci. Philadelphia
Proc., vol. 71, p. 19.
As Dall gives a better description of this species than Emmons,
the description by Dall, in 1903, is here quoted:
A small species attached by the left valve with a strong sulcus near the posterior
dorsal margin of that valve; the free valve obscurely divided into three lobes by
two broad, shallow, radial sulci on the posterior half of the shell; the sculpture is
of fine flutings with occasionally two or more radial series of small, distant, squarish
foliations. The margins are finely crenulate and the average diameter is about 20
mm. The adductor scars are rather long.
Emmons's figure is quite inadequate to give any sufficient idea of the species.
It may prove to be a dynamic mutation of some other species, but Emmons, Meek,
and Conrad, all good judges, regarded it as distinct.
Occurrence: Upper Miocene: Cancellaria zone-station 3421, Har-
veys Creek, half a mile above abandoned mill, Leon County (com-
mon) ; station 1/706, Gully Pond, Washington County (rare) ; station
1/422, Hamlin Pond, Washington County (rare).






92 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Occurrence elsewhere: Miocene: Duplin marl, the Carolinas. Plio-
cene: Waccamaw marl, the Carolinas; Caloosahatchee marl, Florida.

Genus ECHINOCHAMA Fisher, 1887
Echinochama arcinella (Linnaeus)
Plate 19, Figures 1, 4
1767. Chama arcinella Linnaeus, Systema nature, 12th ed., vol. 1, pt. 2, p. 1139.
1789. Cochlea histrix Martyn, Universal conchology, pi. 132, fig. 2.
1789. Cochlea cristagalli Martyn, idem, pl. 132, fig. 1.
1817. Arcinella spinosa Schumacher, Essai d'un nouveau syst6me des habitations
des vers testac6s, p. 142, pl. 13, fig. 1.
1846. Chama arcinella Linnaeus. Reeve, Conchologica Iconica, vol. 4, Chama, pl. 5,
figs. 26, 26a.
1846. Chama arcinella Lamarck. Conrad, Am. Jour. Sci., 2d ser., vol. 1, p. 404.
1853. Chama arcinella Linnaeus. D'Orbigny, in De la Sagra, Histoire physique,
politique et naturelle de 'ile de Cuba, Mollusques de Cuba, vol. 2, p. 362,
pl. 28, figs. 28-29.
1853. Arcinella arcinella Linnaeus. March, Catalogus conchyliorum, Comes de
Yoldi, p. 37.
1855. Chama arcinella Linnaeus. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 22, pl. 7, figs. 4-6.
1857. Chama (Arcinella) spinosa Schumacher. H. and A. Adams, Genera of Recent
Mollusca, vol. 2, p. 464.
1858. Chama arcinella [Linnaeus]. Emmons, North Carolina Geol. Survey Rept.,
p. 287, fig. 209.
1858. Chama arcinella Linnaeus. Holmes, Post-Pleiocene fossils of South Carolina,
p. 23 (pl. 5, fig. 1, excluded).
1863. Arcinella (Chama) arcinella Linnaeus. Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, p. 576.
1864. Chama (Arcinella) arcinella Linnaeus. Meek, Check list of the invertebrate
fossils of North America, Miocene: Smithsonian Misc. Coll., vol. 7, No. 183,
p. 8 (name only).
1866. Arcinella cornuta Conrad, Am. Jour. Conchology, vol. 2, p. 105.
1873. Chama arcinella Linnaeus. Gabb, Geology of Santo Domingo, Am. Philos.
Soc. Trans., vol. 15, p. 251.
1887. Chama arcinella Linnaeus. Heilprin, Wagner Free Inst. Sci. Trans., vol. 1,
p. 103 (name only).
1887. Chama (Echinochama) arcinella Linnaeus. Fischer, Manuel de conchy-
liologie, p. 1049.
1903. Echinochama arcinella Linnaeus. Dall, Wagner Free Inst. Sci. Trans., vol. 3,
pt. 6, p. 1405.
1908. Chama arcinella Linnaeus. Rogers, Shell Book, p. 361, pl. 81, facing p. 357,
fig. 3.
1911. Echinochama arcinella Linnaeus. Vaughan, Georgia Geol. Survey Bull. 26,
p. 378.
1916. Chama arcinella Linnaeus. Mansfield, U. S. Nat. Mus. Proc., vol. 51, p. 601,
pl. 113, figs. 11, 12.
1926. Pseudochama (Echinochama) arcinella (Linnaeus) Odhner. Gardner, U. S.
Geol. Survey Prof. Paper 142-B, p. 94, pl. 17, figs. 14-16.

The shell of this species is equivalve, inequilateral, and inflated.
Umbones broad, swollen, involute, and prosogyrate. Lunule large,
broadly cordate, deeply impressed, and well defined. Escutcheon
obscure. Outline of inner margins subcircular except for a lobate
projection below the lunule. Exterior surface ornamented with vary-
ing number of spinose ribs, the spines being more strongly developed
over the medial portion of the disk. Interspaces and lunule rudely
tuberculated. Right valve provided with a strong corrugated dental






CHOCTAWHATCHEE PELECYPODS


projection which fits into a deep socket of the left valve. Inner mar-
gin of valves crenulate.
Occurrence: Upper middle Miocene: Arca zone-Red Bay, Walton
County (quite rare) ; station 12044, Bell farm, upper locality, Walton
County. Upper Miocene: Ecphora zone-station 8862, near Clarks-
ville, Calhoun County (one small valve) ; station 1/962, cut in old
road leading to Watsons Landing, Liberty County (one small valve.) ;
Permenter's old place, Alaqua Creek, Walton County (one small
specimen). Cancellaria zone-station 3422, uppermost bed at Jackson
Bluff, Leon County (common); station 3421, Harveys Creek, half a
mile above abandoned mill, Leon County (common); station 1/422,
Hamlin Pond, Washington County (two large valves).
The species, as indicated above, is represented by two small valves
in the colder water of the Ecphora zone and by many large individuals
in the warmer water of the Cancellaria zone.
The specimens from the Arca zone and the Shoal River formation
are more inflated than the specimens from the Cancellaria zone.
Occurrence elsewhere: Miocene: Shoal River formation; dredged
from Miocene(?), Brunswick River, Brunswick, Ga. (with a mixed
fauna, Miocene and later); Raysors Bridge, Edisto River, Colleton
County, S. C. Pliocene: Waccamaw marl, the Carolinas; Caloosa-
hatchee marl, Florida. Recent: Hatteras to Sao Paulo, Brazil, in
0-26 fathoms.
Superfamily LUCINACEA
Family LUCINIDAE
Genus CODAKIA Scopoli, 1777
Section JAGONIA R6cluz, 1869
Codakia (Jagonia) magnoliana Dall
Plate 20, Figure 1
1903. Codakia (Jagonia) magnoliana Dall, Wagner Free Inst. Sci. Trans., vol. 3, pt. 6,
pp. 1349-1350, pl. 52, fig. 17.
Dall describes this species as follows:
Shell small, thin, inequilateral, the beaks five-elevenths of the whole length in
front of the posterior end; both ends rounded, base arcuate, lunule narrow, lanceo-
late, no distinct dorsal areas; sculpture of numerous even, fine, close-set, rarely
divaricate, similar radial riblets, crossed by fine, rounded, equal, close-set threads,
narrower than the riblets, and which in crossing the latter are slightly arcuate con-
vexly towards the beaks, making a very elegant though minute type of sculpture;
hinge thin and delicate, but the teeth, especially the right laterals, very distinct;
scars normal; margins delicately crenulate. Height 9.5, length 11.5, diameter
4.5 mm.
This species is of the fully differentiated Jagonia type and its sculpture is
notably elegant.
Upper Miocene of Magnolia, Duplin County, North Carolina; Burns.
The specimen figured by Dall probably represents a juvenile form.
This species has a lower shell than Codakia speciosa (Rogers) and is
sculptured with finer radials.






94 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Occurrence: Upper Miocene: Cancellaria zone-station 3421, Har-
veys Creek, half a mile above abandoned mill, Leon County (quite
common); station 1/955, Gully Pond, Washington County (rare?);
station 1/422, Hamlin Pond, Washington County (one fragment, iden-
tification uncertain).
Outside occurrence: Upper Miocene: Duplin marl, the Carolinas.
Codakia (Jagonia) speciosa (Rogers)?
Plate 20, Figure 5
1837. Lucina speciosa Rogers, Am. Philos. Soc. Trans., new ser., vol. 5, p. 333 (de-
scribed); idem, vol. 6, pl. 26, fig. 6, 1839.
Four small valves collected at station 3423, lower upper Miocene
bed at Jackson Bluff, and one small valve from Harveys Creek, station
1/946, Leon County, Fla., may belong to C. speciosa (Rogers). These
specimens are sculptured with rather coarse radials. In this feature
they agree with specimens occurring in zone 1 and zone 2 (lower part)
of the Yorktown formation of Virginia.
Dalls3 reported Codakia speciosa (Rogers) from a number of
localities in Virginia, from the Duplin marl of the Carolinas, and from
the Pliocene-the Caloosahatchee marl-of Florida. The Virginia
specimens, as a rule, appear to have a more inflated shell than speci-
mens that have been referred to this species from the Miocene-the
Duplin marl-of North Carolina, or from the Pliocene. The speci-
mens from the Duplin marl are marked with finer radials than speci-
mens either from the Yorktown formation of Virginia or from the
Pliocene.
Codakia (Jagonia) leonensis Mansfield, n. sp.
Plate 20, Figures 2, 3, 4
Shell small, rather solid, subovate, equivalve, very inequilateral,
the anterior side being much longer. Beaks low, projecting, approxi-
mate, and weakly prosogyrate. Lunule depressed, wide, and long.
Valves weakly inflated. Anterior and posterior margins narrowly
rounded, ventral margin broadly rounded. Sculpture composed of
six or seven strong radials and usually of one weaker radial intercalat-
ing the stronger radials near the margin. Concentric sculpture con-
sisting of strong, moderately thick, marginally elevated plications,
which are a little stronger over the ribs than in the interspaces. Inner
margin coarsely crenulate.
Cotypes (Cat. No. 371179, U. S. N. M.) measure: Right valve:
Length, 3.2 mm.; height, 3 mm.; diameter, 0.8 mm. Left valve:
Length, 3.6 mm.; height, 3.3 mm.; diameter, 1 mm.
Type locality: Station 3423, lower upper Miocene bed at Jackson
Bluff, Leon County, Fla.
88Dall, W. H., Wagner Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1350, 1903.






CHOCTAWHATCHEE PELECYPODS


The new species is related to Codakia speciosa (Rogers) but differs
from that species in having a more inequilateral shell and stronger
radials.
Occurrence: Upper Miocene: Ecphora zone. Known only from
the type locality.
Genus LUCINA Lamarck, 1799
Lucina chrysostoma (Meuschen) Philippi
Plate 19, Figures 2, 3
1784. Venus edentula Chemnitz, Conchylien-Cabinet, vol. 7, pl. 40, figs. 427-9. (Not
Linne, 1758.)
1787. Tellina chrysostoma Meuschen, Geversianum, p. 482 (err. typ.).
1792. Venus edentula Gmelin, Systema nature, vol. 1, pt. 6, p. 3286. (Not Linn6,
1758.)
1807. Anodonta alba Link, Beschreibung Rostuck Sammlung, p. 156.
1847. Lucina chrysostoma Philippi, Abbildungen und Beschreibungen neue Con-
chylien, 2, p. 206, pl. 1, fig. 3.
1850. Lucina edentula Reeve, Conchologica Iconica, Lucina, pl. 2, fig. 9. (Not
Linn6, 1758.)
1878. Loripes chrysostoma Meuschen. Arango, Fauna Malacol6gica Cubana, p. 257.
1887. Lucina edentula Heilprin, Wagner Free Inst. Sci. Trans., vol. 1, pp. 102-103.
(Not Linn6, 1758.)
1903. Lucina chrysostoma (Menschen) Philippi. Dall, Wagner Free Inst. Sci
Trans., vol. 3, pt. 6, p. 1354.
1909. Lucina chrysostoma Meuschen. Vaughan, Florida Geol. Survey Second Ann.
Rept., p. 121.
The shell of this species is strongly inflated, thin, equivalve, and
nearly equilateral. The sculpture consists of rather fine concentric
lines. The presence of this species in the Cancellaria zone indicates
a rise in temperature of the water over that of the preceding zone.
Occurrence: Upper middle Miocene: Area zone-Red Bay, Walton
County (specimen not well preserved and identification uncertain).
Upper Miocene: Cancellaria zone-station 3421, Harveys Creek, half
a mile above abandoned mill, Leon County (quite common); station
3422, uppermost bed at Jackson Bluff, Leon County (rare?); borrow
pit, Jackson Bluff (common); station 4993, from well 1 mile west of
Holland post office, Leon County (two fragments) ; station 1/422,
Hamlin Pond, Washington County (fragments).
Outside occurrence: Pliocene: Caloosahatchee marl, Florida.
Pleistocene: Southern Florida and south. Living in shallow water
from North Carolina to West Indies.
Genus PHACOIDES Blainville, 1825
Subgenus LINGA de Gregorio, 1884
Section PLEUROLUCINA Dall, 1901
Phacoides (Pleurolucina) choctawhatcheensis. Mansfield
Plate 20, Figures 9, 10
1916. Phacoides (Pleurolucina) choctawhatcheensis Mansfield, U. S. Nat. Mus.
Proc., vol. 51, p. 604, pl. 113, figs. 8, 9.
The type of this species was obtained from the Area zone of the
upper middle Miocene, one-fourth of a mile east of Red Bay, Walton






96 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

County, Fla. It has not been found elsewhere. The species is char-
acterized by its rather broad shell and by its rather unique ornamen-
tation, which consists of four strong diverging ribs and coarse, raised
concentric lamellae. Fine concentric threads lie between these
lamellae. The section Pleurolucina is represented in the Bowden
marl, Jamaica, by P. quadricostatus Dall; in the Pliocene, by P. ama-
bills Dall; and in the Recent, by P. leucocyma Dall. The Recent
species ranges from North Carolina to the West Indies, but the warmer
water of the southern latitude is a more favorable habitat. Although
this species is much larger than the Bowden species, it appears to be
more closely related to it than to the Pliocene species.
Subgenus CARDIOLUCINA Sacco, 1901
Phacoides (Cardiolucina) trisulcatus multistriatus (Conrad)
Plate 20, Figures 15, 16
1843. Lucina multistriata Conrad, Acad. Nat. Sci. Philadelphia Proc., vol. 1, p. 307.
1845. Lucina multistriata Conrad. Conrad, Fossils of the medial Tertiary of the
United States, p. 71, pl. 40, fig. 6.
1863. Codakia (Lucina) multistriata Conrad. Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, p. 577.
1903. Phacoides (Cavilucina) trisulcatus var. multistriatus Conrad. Dall, Wagner
Free Inst. Sci. Trans., vol. 3, pt. 6, p. 1370.
1919. Phacoides (Cavilucina) trisulcatus subsp. multistriatus (Conrad). Garner
and Aldrich, Acad. Nat. Sci Philadelphia Proc., vol. 71, p. 19.
Conrad described this subspecies in 1843 as follows:
Oval, equilateral, slightly ventricose, with fine, prominent, closely arranged
concentric and minute radiating lines. Disk with two or more distinct undulations
on the inferior half; beaks prominent; dorsal margins profoundly declining;
anterior lateral tooth distinct, remote; inner margin minutely crenulated; lunule
elliptical, slightly impressed. Height one-third of an inch. Locality, Wilming-
ton, N. C.
This subspecies is closely related to Phacoides trisulcatus (Con-
rad), a species described from the Duplin marl at the Natural Well,
N. C., and may represent a mutation of that species. P. trisulcatus has
more pronounced and more numerous resting stages than the sub-
species multistriatus.
Occurrence: Upper Miocene: Cancellaria zone-station 3421, Har-
veys Creek, half a mile above abandoned mill, Leon County (com-
mon) ; station 3671, 2 miles north of Hosford, Liberty County (rare);
station 3672, 2% miles northwest of Hosford (rare); station 1/706,
Gully Pond, Washington County (rare).
Outside occurrence: Upper Miocene: Yorktown formation, highest
zone, Virginia and North Carolina; Duplin marl, the Carolinas.
Phacoides trisulcatus (Conrad) occurs in the Duplin marl of the
Carolinas, in the Pliocene Caloosahatchee marl of Florida, and among
the Recent fauna from Cape Hatteras to Cape Rouge.
Gardner84 reported Phacoides (Cardiolucina) trisulcatus (Conrad)
from the Chipola formation of Florida. The Chipola form has a
s4Gardner, Julia, U. S. Geol. Survey Prof. Paper 142-C, p. 108, 1926.






CHOCTAWHATCHEE PELECYPODS


Much deeper depression in front of the posterior margin than the
specimens from the Duplin marl and appears to represent another
species or subspecies. The specimens figured by Glenns5 under the
name Phacoides (Here) trisulcatus (Conrad) appear to be more
closely related to Phacoides prunus Dall than to P. trisulcatus Conrad.

Subgenus LUCINISCA Dall, 1901
Phacoides (Lucinisca) cribrarius (Say)
Plate 21, Figures 22, 23
1824. Lucina cribraria Say, Acad. Nat. Sci. Philadelphia Jour., vol. 4, p. 147, pl. 13,
fig. 1.
1838. Lucina cribraria Say. Conrad, Fossils of the medial Tertiary of the United
States, pl. 3, fig. 1.
1842. Lucina cribraria Say. Conrad, Nat. Inst. for Promotion of Science Proc.,
vol. 2, p. 187. (Listed with "Organic remains found on St. Marys River,"
Md.)
1856. Lucina cribraria Say. Tuomey and Holmes, Pleiocene fossils of South Caro-
lina, p. 58, pl. 18, figs. 8, 9.
1863. Codakia (Lucina) cribraria (Say). Conrad, Acad. Nat. Sci. Philadelphia
Proc. for 1862, vol. 14, p. 577. (In part, not Emmons, 1858.)
1903. Phacoides (Lucinisca) cribrarius (Say). Dall, Wagner Free' Inst. Sci. Trans.,
vol. 3, pt. 6, p. 1372.
1904. Phacoides (Lucinisca) cribrarius (Say). Glenn, Maryland Geol. Survey,
Miocene, p. 341.
1911. Phacoides cribrarius (Say). Vaughan, Georgia Geol. Survey Bull. 26, p. 368.
(Listed with fauna from upper Miocene horizon at Porters Landing, Ga.)
1919. Phacoides (Lucinisca) cribrarius Say. Gardner and Aldrich, Acad. Nat. Sci.
Philadelphia Proc., vol. 71, p. 19. (Listed with fauna from locality near
Mayesville, S. C.)
Say described this species in 1824 as follows:
Shell with close set, longitudinal, equal, granulated ribs, and more or less
elevated, distinct, concentric lamellae; hinge margin obtusely and not prominently
angulated at its anterior and posterior terminations; anterior margin with a dilated,
slightly impressed, and not very obvious groove; lunule oblong-oval, very distinct,
the edge near the beaks extending inwards beside the primary teeth; lateral teeth
very distinct, the posterior one placed nearly under the middle of the lunule;
within crenate on the edge; posterior muscular impression rectilinear.
Length half an inch, breadth eleven-twentieths of an inch.

This species appears to be the precursor of Phacoides (Lucinisca)
nassula caloosana Dall, a subspecies occurring in the Pliocene Caloosa-
hatchee marl of Florida, but differs mainly from its descendant in
having a more inflated shell and in being marked with stronger radials.
Occurrence: Upper Miocene: Ecphora zone-station 2210, upper
bed at Alum Bluff, Liberty County (quite rare) ; station 8862, half a
mile northeast of Clarksville, Calhoun County (rare); station 1/965,
lower upper Miocene bed at abandoned mill on Harveys Creek, Leon
County (rare); Permenter's old place, Alaqua Creek, Walton County
(G. M. Ponton, collector). Cancellaria zone-station 3671, 2 miles
north of Hosford, Liberty County (abundant); station 3672, 234
miles northwest of Hosford (abundant) ; station 3422, uppermost bed
at Jackson Bluff, Leon County (common) ; borrow pit, Jackson Bluff,
s5Glenn, L. C., Maryland Geol. Survey, Miocene, pl. 90, figs. 7-9, 1904.





98 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Leon County (common) ; station 1/964, highest bed at abandoned mill
on Harveys Creek, Leon County (rare); Harveys Creek, half a mile
above the abandoned mill (one valve).
Outside occurrence: Upper Miocene: Yorktown formation, Vir-
ginia and North Carolina, zone 1 and later; Duplin marl of the
Carolinas.
Say"8 reported the type specimen from St. Marys County, Md.
Glenn87 is of the opinion that. Say's type really came from Virginia.
I am of the same opinion, as I have not found this species in Maryland,
nor in the St. Marys formation of Virginia.
The specimens from the Ecphora zone in Florida are usually a
little more inflated than those in the succeeding Cancellaria zone but
otherwise are very similar. This species appears to be represented
by fewer individuals in the latest Miocene beds, where the fauna indi-
cates a rising temperature of the sea.

Subgenus PSEUDOMILTHA Fischer, 1887
Phacoides (Pseudomiltha) anodonta (Say)
Plate 20, Figure 19
1824. Lucina anodonta Say, Acad. Nat. Sci. Philadelphia Jour., vol. 4, p. 146, pl. 10,
fig. 9.
1840. Lucina anodonta Say. Conrad, Fossils of the medial Tertiary of the United
States, p. 39, pl. 20, fig. 4.
1856. Lucina anodonta Say. Tuomey and Holmes, Pleiocene fossils of South Car-
olina, p. 55, pl. 18, fig. 2.
1903. Phacoides (Pseudomiltha) anodonta (Say). Dall, Wagner Free Inst. Sci.
Trans., vol. 3, pt. 6, p. 1378.
1904. Phacoides (Pseudomiltha) anodonta (Say). Glenn, Maryland Geol. Survey,
Miocene, p. 337, pl. 90, figs. 3, 4.
1919. Phacoides (Pseudomiltha) anodonta (Say). Gardner and Aldrich, Acad. Nat.
Sci. Philadelphia Proc., vol. 71, p. 19.
Say described this species in 1824 as follows:
Orbicular, slightly transverse, compressed; teeth obsolete.
Shell with elevated wrinkles; orbicular, a little transverse, with a very slight
impressed longitudinal line on the anterior margin; anterior and posterior ends
equally curved; apices not prominent beyond the general curve of the shell, with
a very short deep emargination behind them; teeth obsolete; both the cardinal and
lateral ones are generally altogether wanting; lunule short, cordate, profound.
Length from the apices to the base one inch and one-tenth, breadth one inch
and one-fifth.
The impressed line on the anterior part of the shell is hardly visible in many
specimens, and is sometimes only a very slight undulation, not observable but on
close inspection.
This species is characterized by its heavy shell, obsolete hinge
teeth, and by its irregularly wrinkled, concentric sculpture.
Occurrence: Upper middle Miocene: Arca zone-station 12046,
Vaughan Creek, upper locality, Walton County (four valves in all,
three of which were collected by Mr. G. M. Ponton, of the Florida
Survey). Ecphora zone-Clarksville (rare)
6Say, Thomas, Acad. Nat. Sci. Philadelphia Jour., vol. 4, p. 147, 1824.
87Glenn, L. C., Maryland Geol. Survey, Miocene, p. 341, 1904.






CHOCTAWHATCHEE PELECYPODS


Outside occurrence: This species, which includes variable forms,
ranges from the Calvert formation of the Chesapeake group (Mio-
cene) to the Pliocene. The shell of this species from the Calvert and
Choptank formations is larger and thinner than that in the succeed-
ing St. Marys formation. In the lower part of the Yorktown forma-
tion, especially that part below the comminuted series in Virginia, the
shell attained a rather large size and occurs rather abundantly; but
' in the later Yorktown, Duplin, and Pliocene it is rare and undersized.
The shell from station 12046 more closely resembles the form that
occurs either in the St. Marys formation or the lower part of the York-
town formation, of the Chesapeake group.
Phacoides (Pseudomiltha) paranodonta Gardner, a species occur-
ring at a number of localities in the Shoal River formation, has a
thinner and lower shell than P. anodonta.
Subgenus LUCINOMA Dall, 1901
Phacoides (Lucinoma) contracts (Say)
Plate 20, Figure 23
1824. Lucina contract Say, Acad. Nat. Sci. Philadelphia Jour., vol. 4, pp. 145, 146,
pl. 10, fig. 8.
1840. Lucina contract Say. Conrad, Fossils of the medial Tertiary of the United
States, p. 40, pl. 20, fig. 5.
1841. Lucina subplanata Conrad, Acad. Nat. Sci. Philadelphia Proc., vol. 1, p. 29.
1842. Lucina subplanata Conrad. Conrad, Acad. Nat. Sci. Philadelphia Jour., 1st
ser., vol. 8, p. 184.
1842. Lucina subplanata Conrad. Conrad, Nat. Inst. for Promotion of Science
Proc., vol. 2, p. 181.
1856. Lucina contract Say. Tuomey and Holmes, Pleiocene fossils of South Car-
olina, p. 54, pl. 18, fig. 1.
1863. Lucina contract Say. Conrad, Acad. Nat. Sci. Philadelphia Proc. for 1862,
p. 577.
1863. Lucina subplanata Conrad. Conrad, idem.
1864. Lucina contract Say. Meek, Check list of the invertebrate fossils of North
America, Miocene: Smithsonian Misc. Coll., vol. 7, No. 183, p. 8.
1864. Lucina subplana Conrad (err. pro subplanata), idem.
1903. Phacoides (Lucinoma) contracts (Say). Dall, Wagner Free Inst. Sci. Trans.,
vol. 3, pt. 6, p. 1380.
1904. Phacoides (Lucinoma) contracts (Say). Glenn, Maryland Geol. Survey,
Miocene, p. 339, pl. 90, figs. 5, 6.
Say described this species in 1824 as follows:
Shell convex, suborbicular, with numerous concentric, regular, equidistant, ele.
vated, membranaceous striae, and intermediate smaller transverse lines; umbones
not very prominent; apices proximate, nearly central; anterior hinge margin
rectilinear, to an obtuse angle near the middle of the anterior margin; anterior
submargin with a very slightly impressed line; posterior margin rounded; cardinal
teeth one in the left valve, and two in the right, the posterior one of which is sub-
bifid at tip; lateral teeth none; within obsoletely striated towards the margin;
posterior muscular impression perfectly rectilinear, elongated, and oblique.
Length one inch and nine-tenths, breadth two inches and one-tenth.
Occurrence: Upper Miocene: Ecphora zone-station 2210, upper
bed at Alum Bluff, Liberty County, Fla. (quite common, Frank Burns,
collector; also obtained from this place by other collectors); Per-
menter's old place, Alaqua Creek, Walton County (one specimen).






100 FLORIDA GEOLOGICAL SURVEY-BULLETIN EIGHT

Outside occurrence: Maryland-Calvert, Choptank, and St. Marys
formations. Virginia-Calvert, Choptank, St. Marys, and Yorktown
formations. Carolinas-Yorktown formation.
Although this species is reported by Tuomey and Holmes from
the Darlington district of South Carolina, it appears to be very rare
or wanting in the Duplin marl of the Carolinas or marls of equiva,
lent age.
Subgenus PARVILUCINA Dall, 1901
SPhacoides (Parvilucina) crenulatus (Conrad)
Plate 20, Figures 20, 22
1840. Lucina crenulata Conrad, Fossils of the medial Tertiary of the United States,
p. 39, pl. 20, fig. 2.
1845. Lucina lens H. C. Lea, Am. Philos. Soc. Trans., vol. 9, p. 240, pl. 34, fig. 19.
1856. Lucina crenulata Conrad. Tuomey and Holmes, Pleiocene fossils of South
Carolina, p. 60, pl. 18, figs. 14, 15.
1858. Lucina crenulata Conrad. Emmons, North Carolina Geol. Survey Rept., p.
291, fig. 217.
1863. Lucina crenulata Conrad. Conrad, Acad. Nat. Sci. Philadelphia Proc. for
1862, vol. 14, p. 577.
1864. Lucina crenulata Conrad. Meek, Check list of the invertebrate fossils of
North America, Miocene: Smithsonian Misc. Coll., vol. 7, No. 183, p. 8.
1894. Lucina crenulate Conrad. Whitfield, U. S. Geol. Survey Mon. 24, p. 63, pl. 10,
figs. 7.15. (?Not Conrad, 1840.)
1903. Phacoides (Parvilucina) crenulatus Conrad. Dall, Wagner Free Inst. Sci.
Trans., vol. 3, pt. 6, p. 1383, pl. 52, fig. 12.
The original locality of this species is Suffolk, Va.
The shell is moderately convex, slightly inequilateral, rather solid.
The posterior side is moderately depressed in front of the dorsal
margin. The sculpture consists of rather strong and closely set con-
centric lamellae and closely set radial threads which do not cancellate
the concentric lamellae. The hinge is well developed. The lunule
is moderately deep.
Occurrence: Upper middle Miocene: Area zone-Red Bay, Walton
County (abundant); station 12044, Bell farm, upper locality, Walton
County (common); station 12045, Bell farm, lower locality; station
12046, Vaughan Creek, upper locality (abundant); station 12047,
Vaughan Creek, lower locality (rare?); station 12060, Frazier farm,
Walton County (rare?); station 12267, Taylor branch on Bryant
Scott's farm, Bay County (common). Upper Miocene: Ecphora
zone-station 3423, lower upper Miocene bed, Jackson Bluff, Leon
County (rare); station 1/965, lower upper Miocene bed at abandoned
mill, Harveys Creek, Leon County (rare). Cancellaria zone-station
1/964, uppermost bed at abandoned mill, Harveys Creek (one valve);
station 3422, uppermost bed at Jackson Bluff, Leon County (two
specimens); Harveys Creek, half a mile above abandoned mill (one
specimen).
Outside occurrence: Miocene: Chesapeake group, Maryland, Vir-
ginia, North Carolina; Duplin marl, the Carolinas.