Additions to the molluscan fauna of the Alum Bluff group of Florida (FGS: Bulletin 14)

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Material Information

Title:
Additions to the molluscan fauna of the Alum Bluff group of Florida (FGS: Bulletin 14)
Series Title:
Geological bulletin - Florida Geological Survey ; 14
Physical Description:
82 p. : incl. 10 pl. ; 23 cm.
Language:
English
Creator:
Gardner, Julia Anna, b. 1882
Donor:
unknown ( endowment ) ( endowment )
Publisher:
State Board of Conservation, Geological Department
Place of Publication:
Tallahassee, Fla.
Publication Date:
Copyright Date:
1936

Subjects

Subjects / Keywords:
Mollusks, Fossil   ( lcsh )
Paleontology -- Florida   ( lcsh )
Genre:
non-fiction   ( marcgt )

Notes

Statement of Responsibility:
by Julia Gardner, United States Geological Survey.

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 - AAA1611
notis - AKM4769
alephbibnum - 002037008
oclc - 01656379
lccn - gs 36000131
System ID:
UF00000450:00001

Full Text



STATE OF FLORIDA
DEPARTMENT OF CONSERVATION
GEORGE W. DAVIS, Supervisor


696


GEOLOGICAL BULLETIN No. 14







ADDITIONS TO THE MOLLUSCAN FAUNA OF THE
ALUM BLUFF GROUP OF FLORIDA


BY
JULIA GARDNER
United States Geological Survey







Published by
State Board of Conservation
Geological Department
Tallahassee, 1936






I -) I

Ci~


(I3Cy


Published February 26, 1936


..
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*0 *








LETTER OF TRANSMITTAL


Honorable George W. Davis,
Supervisor of Conservation.

DEAR MR. DAVIS:

The Florida Geological Survey has received from the
United States Geological Survey the manuscript of a short
paper entitled "Additions to the Molluscan Fauna of the
Alum Bluff Group of Florida" by Dr. Julia Gardner. In
1926 the Federal Survey published as Professional Paper 142
a comprehensive treatment of the fauna of the Alum Bluff
group of formations of Florida and the present short paper
is a supplement, based largely on collections made subse-
quently. It will make therefore the treatment of the fauna
of this interesting group more complete. This paper is a
contribution from the Federal Survey, the only expense being
that of publication. It is with deep appreciation that
acknowledgment of this generous cooperation is made. I
recommend that it be published as Geological Bulletin No. 14.
Very respectfully,
HERMAN GUNTER, Assistant Supervisor,
State Board of Conservation,
Geological Department.
Tallahassee, Florida,
December 3, 1935.




f1722






















CONTENTS
PAGE
Introduction 7
Distribution of the fauna 8
Systematic descriptions 9



ILLUSTRATIONS

Plates 1-10. Additions to the Molluscan Fauna of the
Alum Bluff Group of Florida 62









ADDITIONS TO THE MOLLUSCAN FAUNA OF THE
ALUM BLUFF GROUP OF FLORIDA1
BY
JULIA GARDNER

INTRODUCTION

Although a comparatively short space of time has elapsed
since the publication of the Molluscan Fauna2 of the Alum
Bluff group,3 subsequent collections, the most of which have
been made by the Florida State Geological Survey, have
yielded a number of mollusks of unusual interest. Many of
the finest specimens are undescribed and others exhibit new
characters of importance in the discussion of known species.
The incompleteness of our published record so clearly indi-
cated is in accord with estimates based on crude comparisons
with the Recent faunas. A rough count of the existing fauna
listed by Johnson4 includes between 400 and 450 pelecypods
from the east coast of Florida. There is no apparent reason
to assume that the warm water lower and middle Miocene
faunas numbered appreciably fewer species than the Recent.
The Chipola fauna, probably the warmest water and the most
prolific, has yielded not quite 200 pelecypods, something less
than half the postulated fauna at the time of deposition.
Many of the missing have doubtless left no record, but it is
probable that even in casual collections made for many years
to come, undescribed species or interesting examples of al-
ready described forms will see the light.


1Published by permission of the Director, U. S. Geological Survey,
Washington, D. C.
20nly the report upon the bivalves has appeared. The first of
the parts covering the gastropods is now in press. The rest will
follow.
3Gardner, Julia, The molluscan fauna of the Alum Bluff group
of Florida: U. S. Geol. Survey Prof. Paper 142, pp. 1-249; pls.
1-36, 1926-1928.
'Johnson, Charles W., List of marine Mollusca of the Atlantic
Coast from Labrador to Texas: Boston Soc. Nat. Hist., Proc., vol.
40, no. 1, pp. 1-204, July, 1934.




8 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

The present appendix covers the most of the new bivalves
that have appeared since the publication on the Alum Bluff
fauna and a few gastropods common to the Shoal River, the
uppermost of the formations of the Alum Bluff group, and
the Choctawhatchee, which overlies the Alum Bluff. In
working up the Choctawhatchee gastropods, Dr. W. C. Mans-
field' came upon a number of species common to the Choctaw-
hatchee and the Shoal River. As the Alum Bluff gastropods
had already been named, described and figured, Doctor Mans-
field most courteously and most kindly has, in his published
bulletins, made mention of these common forms by their
generic determinations only. Some of the descriptions and
figures of the Alum Bluff gastropods are already in the hands
of the editor or the printer, but those forms still in my pos-
session, which occur both in the Choctawhatchee and the Shoal
River, have been included with the bivalves.
I am greatly indebted to Nelson W. Shupe of the U. S.
Geological Survey, who has made the photographs, and to
Miss Frances Wieser who has retouched them.
DISTRIBUTION OF THE FAUNA
The following list shows the localities cited by number in
Ilie text.
2238. Flournoy's mill race, 2 miles east of Argyle, and 5 miles
east of DeFuniak Springs, near railroad, Walton Coun-
ty, Fla.
2646. Oak Grove, west bank of Yellow River, Okaloosa County,
Fla.
3731. Near Mossyhead, see. 6, T.3 N., R.21 W.. Walton County,
Fla.
3732. Dave Adams' Mill Creek, sec. 2, T. 3 N., R. 21 W., Walton
County, Fla.
3733. Three-fourths mile west of Shell Bluff Landing, Shoal River.
Walton County, Fla.
3742. Shell Bluff, Shoal River, Walton County, Fla.
3748. Summerville mill race, 1 mile east of Argyle, Walton
County, Fla.
3856. 6 miles west-northwest of Mossyhead, Walton County, Fla.
5Mansfield, W. C., Miocene gastropods and scaphopods of the
Choctawhatchee formation of Florida: Florida State Geol. Survey,
Bull. No. 3, pp. 1-189; pls. 1-21, 1930. New Miocene gastropods and
scaphopods from Alaqua Creek Valley, Florida: State of Florida
Dept. Conservation, Geol. Bull. No. 12, pp. 1-64: pls. 1-5, 1935.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 9

5079. One-half mile below Shell Bluff. Shoal River. Walton Coun-
ty, Fla.
5080. At head of first ravine below Shell Bluff, 200 yards north
of Shoal River, Walton County, Fla.
5184. At head of first ravine below Shell Bluff, 200 yards north
of Shoal River, Walton County, Fla.
5195. At head of first ravine below Shell Bluff, 200 yards north
of Shoal River, Walton County. Fla.
5618. 31/ miles southwest of De Funiak Springs, Walton County,
Fla.
5632. Oak Grove, Yellow River, Okaloosa County, Fla.
5633. Below Oak Grove Bridge, Yellow River, Okaloosa County,
Fla.
6800. Preston Sink, 3 miles north of Waldo. Alachua County,
Fla.
7054. 400 feet below bridge, Oak Grove, Okaloosa County, Fla.
7261. Upper Alaqua Lethu(?) Bluff, near De Funiak Springs,
Walton County, Fla.
7264. De Funiak Cardium Zone, Alaqua, Walton County, Fla.
9957. Gully south of the road and east of the bridge over White's
Creek, on road from Eucheeanna to Knox Hill, 6.7 miles
south of Argyle, 1.7 miles southeast of Eucheeanna, Wal-
ton County, Fla.
9958. Site of Flournoy's old mill, about 11/ miles northeast of
Argyle, Walton County, Fla.
9959. One-fourth mile west by north of Pleasant Ridge Church,
5.2 miles southwest of De Funiak Springs, SW. 1/4, SE.
1/, sec. 6, T. 2 N., R. 19 W. (Cardium zone of Shoal River),
Walton County, Fla.
9960. Folk's Creek, 6 miles south of Argyle and 1.7 miles from
Eucheeanna, Walton County, Fla.
10603. Gully south of the road and east of the bridge over White's
Creek, on road from Eucheeanna to Knox Hill, 6.7 miles
south of Argyle, 1.7 miles southeast of Eucheeanna, Wal-
ton County, Fla.
10608. White's Creek, half a mile below bridge on Encheeanna-
Knox Hill road, Walton County, Fla.
11003. Six miles west of Greensboro, Gadsden County, Fla.
SYSTEMATIC DESCRIPTIONS
Anadara (strebla subsp.?) metastrebla Gardner, new species
Plate 1, Figures 1, 2
Shell rather small for the group and moderately heavy,
transversely elongated, broadly inflated from the umbones
to the ventral margin, the curvature of the anterior portion





10 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

of the shell higher than that of the posterior. Anterior later-
al margin rounding very broadly and smoothly into the base.
Posterior margin slightly constricted at the hinge line, broad-
ly arcuate. No defined posterior area. Hinge line approxi-
mately parallel to the ventral margin and about three-fourths
the width of the shell. Umbones broad and full, the tips
compressed and feebly sulcate medially, bent forward and
inward above the low cardinal area. Sculpture similar on
the two valves. Radials 40 in the type, 37 to 41 in other
specimens from the type locality, simple, moderately elevated,
more narrow medially than toward the lateral margins. In-
crementals cross-hatching the interradials and corrugating
the radials, strongest toward the anterior margin, obsolete
posteriorly. Cardinal area narrow, grooved in crude chev-
rons, the angle of the chevron slightly posterior to the tips of
the umbones. Hinge narrow, very finely and closely serrate;
34 teeth in the anterior dental series of the type, 41 in the
posterior; the line between the two series inconspicuous and
in worn specimens, obliterated, but posterior both to the tips
of the umbones and to the angle of the ligament grooves.
Adductor scars large, distinct, set high up near the distal
extremities of the hinge. Pallial line simple, not very close
to the crenate ventral margin.
Dimensions of holotype, left valve: Height, 22.3 milli-
meters; width, 35.6 millimeters; thickness, 9.9 millimeters.
Type material: Holotype, a left valve, U. S. Nat. Mus. No.
372891.
Type locality: Collected by the State Geological Survey of
Florida. In a gully on the east side of White's Creek, 200
feet south of the bridge on the road to Knox Hill, 6.7 miles
by road south of Argyle and about 1.7 miles southeast of
Eucheeanna, Walton County, Florida. Shoal River forma-
tion of the Alum Bluff group.
Anadara metastrebla differs from the forms to which it
holds a possible subspecific relationship in the lower umbones,
and the less inflated and more regular outline. In Anadara
strebla, the anterior portion of the shell is distinctly more in-
flated than the posterior and the ventral margin slightly con-
stricted posteriorly giving to the shell a somewhat warped
aspect. In A. metastrebla, the inflation is not so great and





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 11

more uniform and the ventral margin is approximately pa-
rallel to the hinge line. This possible subspecies does not
seem to be in the line of evolution with any of the described
species from the Choctawhatchee formation. Anadara aresta
Dall, a possible descendant of A. strebla is farther removed
from metastrebla than from strebla.
There are other species represented in the White's Creek
fauna which have not been reported from the Shoal River
formation, one of them suggesting Anadara lienosa (Say),
which is first recorded from the Choctawhatchee. The ma-
terial is, however, either imperfect or immature, and does
not merit description.
Distribution: Shoal River formation, localities 106031,0
106081', and the collections of the State Survey of Florida.
Anadara gunteri Gardner, new species
Plate 1, Figures 3, 4
Shell of moderate dimensions, inflated, not very heavy, the
left valve a little larger and more inflated than the right.
Trigonal in the exterior view, the interior, excluding the
cardinal area and the prominent umbones subrhomboidal.
Umbones full, conspicuously elevated, incurved and pro-
sogyrate, the apices falling within the anterior third. An-
terior margin drawn in a little at the hinge, broadly and
feebly rounded, merging smoothly into the base line which
may be slightly compressed in front of the posterior rostrum.
Rostrum obtuse but well defined from the umbones to the ven-
tral margin. Posterior area obliquely flattened, the posterior
margin intercepting the dorsal at an angle greater than 90
degrees. Valves differentially sculptured, the ribs upon the
left running a little higher than those upon the right, more
closely spaced, more elevated, and more nodose. Ribs of
right valve running from 23 to 26, average 25, those of the
type 25 in number, excluding the 8(or 9 in the type), upon
the posterior slope; costals on anterior part of the shell cor-
rugated by the incrementals and medially sulcate, the groove
being deepest, the wrinkles heaviest, and the spacing widest
along the curve from the anterior to the medial portion of
"pr, Prolific; a, abundant; c, common; p, present; r, rare (not
more than half a dozen individuals). Numbers indicate U. S.
Geological Survey Stations.





12 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

the shell; depression in front of the posterior keel empha-
sized by the disappearance of ornamentation upon the costae
and by their relatively wide spacing. Posterior ribs relative-
ly narrow, rounded and feebly corrugated. Probably one
more rib in the left valve than in the right, though there are
no double valves in the collection; ribs of left valve cor-
rugated or nodose and feebly sulcate upon the anteromedial
arch, narrower and less closely spaced posteriorly than upon
the medial portion of the shell. Inner margins fluted in
harmony with the external ribbing. Cardinal area rather
narrow, rudely kite-shaped in the double valves, scored with
a few ligament grooves which are rudely parallel to the outer
margins. Hinge narrow, broadly constricted medially, fine-
ly serrate; the teeth not far from 50 to the valve, striated
upon their lateral surfaces, tending to become bent and ir-
regular toward the distal extremities. Muscle impressions
rather large, well defined, the posterior larger, less regular,
and more remote from the hinge than the anterior. Pallial
line running parallel and rather close to the outer margin.
Dimensions of cotypes: Right valve, height, 29.5 milli-
meters; width, 37.3 millimeters; thickness, 12.0 millimeters.
Left valve of another individual, height, 26.0 millimeters;
width, 30.0 millimeters; thickness, 13.0 millimeters.
Type material: Two cotypes, a right and a left valve not
of the same individual, U. S. Nat. Mus. No. 372882.
Type locality: U. S. G. S. Sta. No. 10603, gully south of
the road and east of the bridge over White's Creek, on road
from Eucheeanna to Knox Hill, 6.7 miles south of Argyle,
1.7 miles southeast of Eucheeanna, Walton County, Florida.
Shoal River formation of the Alum Bluff group.
I have the pleasure of naming this species in honor of
Herman Gunter, the State Geologist of Florida, to whose
interest and intelligent cooperation we of the Government
service have long been indebted.
Anadara gunteri is doubtless a member of the group of
staminata of the Chipola fauna, santarosana of the Oak Grove
and waltonia of the Shoal River. It is the least inflated of
them all and the hinge area narrows with the less distant
umbones. The shell is not so heavy as it is in other
members of the Alum Bluff group and the muscle impres-






ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 13

sions, particularly the posterior, are less conspicuous. The
species is restricted in its known distribution to the exposures
of the Shoal River beds along White's Creek in Walton
County.
Distribution: Shoal River formation, localities 10603c,
10608c.
Crenella armstrongi Gardner, new species
Plate 1, Figures 5, 6
Shell minute, roughly elliptical, inflated. Lining of shell
chalky white against the gray subnacreous outer layer. Pro-
dissoconch distinct porcellanous not greatly inflated smooth.
Umbones inconspicuous, slightly anterior and feebly proso-
gyrate. Radials usually simple along the flanks of the shell,
divaricate medially; the number at the periphery in the
neighborhood of 70. Ligament opisthodetic, the area of at-
tachment very narrow, extending from directly underneath
the beaks more than two-thirds the length of the posterior
dorsal margin. Provinculum of 4 to 6 subumbonal taxodont
vertical teeth. Posterior dorsal margin very finely serrate
along the inner surface, the teeth less narrow away from the
beaks. Entire margin with the exception of the posterior
dorsal which is simple along the edge, finely create in har-
mony with the radials; characters of interior obscure.
Dimensions of holotype, left valve: Height, 4.0 milli-
meters; width, 3.0 millimeters. Paratype, right valve:
Height, 2.3 millinmters; width, 1.8 millimeters.
Type material: Holotype and paratype, U. S. Nat. Mus.
No. 372864.
Type locality: U. S. G. S. Sta. No. 9960, Folk's Creek,
sec. 21 or 22, T. 3 N., R. 18 W., 6 miles south of Argyle and 1.7
miles south of Eucheeanna, Walton County, Florida. Shoal
River formation, Alum Bluff group.
The species is named in honor of Mr. J. M. Armstrong,
who was my friendly guide while I was working in east-cen-
tral Walton County. To him, to Mrs. Armstrong, and to
their children I am very grateful for the pleasant memories of
my field work in the area.
Crenella armstrongi is larger and less inflated than
Crenella minuscula which Dall described from the Chipola





14 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

formation. In general characters both species are very close
to the type of the genus, Crenella decussata (Montagu) recent
in the North Atlantic.
Distribution: Shoal River formation, locality 9960'.
Lithophaga cookei Gardner, new species
Plate 8, Figures 5-7
Molds of double valves, slender, tapering, stream line cyl-
inders. Beaks terminal, or nearly so, conforming to the curv-
ature of the burrow. Ligament groove extending about half
the length of the dorsal margin. Fragments of an exceed-
ingly thin shell adhering to the mold. Calcareous coating a
millimeter thick anteriorly, possibly not quite so thick or
thicker posteriorly, apparently without structure, terminat-
ing posteriorly in a sort of stalk compressed parallel to the
longer axis of the shell.
Dimensions of holotype, mold of double valves: Height,
8.8 millimeters; width, 23.2 millimeters; thickness, 8.3 milli-
meters.
Type material: Holotype (double valves) and paratype
(individual encased in a calcareous coating), U. S. Nat. Mus.
No. 372902.
Type locality: U. S. G. S. Sta. No. 6800, Preston Sink,
3 miles north of Waldo, Alachua County, Florida. Haw-
thorn formation? of the Alum Bluff group.
The species is named in honor of the collector, Dr. Wythe
Cooke of the U. S. Geological Survey.
These slender coated flasks are not uncommon at the type
locality and are well characterized by their slender stream
line forms.
Distribution: Hawthorn formation, locality 6800P.
Pecten (Pecten) species
The much worn left valve of a true Pecten more than
50.0 millimeters in height is included in the 10603 collection
from White's Creek. It is interesting because of a suggested
relationship to the species from Red Bay figured by Mans-
field under Pecten (Pecten) macdonaldi Olsson.
Chlamys (Lyropecten) nematopleura Gardner, new species
Plate 2, Figure 1; Plate 3, Figure 2
Shell large, not very heavy, sub-equivalve, sub-equilater-
al, showing a strong individual variation in relative dimen-





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 15

sions, not very much inflated; apical angle greater than 90.
Tips of the umbones flattened, sculptured with 15 simple
smooth rounded ribs, with smooth simple intercostal areas.
Costals becoming scabrous a millimeter more or less away
from the umbones and intercalaries introduced, first a medial
thread, then one on either side; number of costal threads in-
creased to three; primary ribs broadening and flattening about
3 centimeters away from the tips of the umbones and in-
dicated on the adult shell only by a feeble rippling. Costal
and intercostal threads scabrous, continuing to increase by
intercalation, the sculpture toward the ventral margins sug-
gesting that of P. clintonius of the section Placopecten al-
though the umbones of that species are unsculptured and pri-
mary ribbing is not developed at any stage in the growth of
the shell. Submargins exceedingly narrow on the right valve,
wider on the left. Auricles very large, the width of the dorsal
margins appreciably more than half the maximum width of
the valve. Byssal groove wide, sharply delimited, incremen-
tally furrowed. Right anterior auricle coarsely threaded
with about 6 lirae radiating fan-like from the tip of the um-
bone to the curved lateral margin; right posterior auricle
large but not so wide as the anterior, deltoid, closely threaded
with lirae similar to but finer than those upon the disk, the
lateral margin almost vertical though slightly drawn in at
the dorsal extremity. Left auricles imperfectly preserved
but apparently similar to the right posterior auricle in size
and sculpture. Ctenolium very coarse. Ligament grooves
co-extensive with the dorsal margins of the auricles. Resilium
deep, trigonal, the margins raised and thickened. Hinge
area reinforced from the inner margin of the resilium to the
outer dorsal extremities of the hinge but no defined crura
observed. Adductor scars obscure. Interior retaining
traces of the primary ribbing pattern which strengthen ven-
trally and crenate the inner margin, the lirae similar in char-
acter to those of Amusium.
Dimensions of holotype, right valve: Height, 100.0+
millimeters; width, 95.0+ millimeters; thickness, 11.5 milli-
meters.
Type material: Holotype, one right valve, U. S. Nat.
Mus. No. 372895.





16 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Type locality: U. S. G. S. Sta. No. 11003, 6 miles west of
Greensboro, Gadsden County, Florida. Collected by the Flor-
ida Survey. Hawthorn formation of the Alum Bluff group.
Chlamys (Lyropecten) nematopleura is closely related
to Lyropecten sayanus Dall from the Oak Grove. The Haw-
thorn species is apparently higher although the broken speci-
mens, of which there are many, indicate that the holotype is
an abnormally high individual. The most obvious distinction
is the persistence of the primary ribs in the Oak Grove
species. They broaden and weaken to be sure toward the
ventral margin but this tendency is not manifested so early
in the growth of the shell nor is it continued to such a degree
as it is in the Gadsden County material. The species C.
nematopleura is common at the type locality, the only locality
in which it has been recognized, but the valves are broken
though not greatly worn.
Distribution: Hawthorn formation, locality 11003c.
Chlamys (Lyropecten?) nicholsi neotera Gardner, new subspecies?
Plate 2, Figures 2, 3
1926. Chlamys (Plagioctenium) nicholsi Gardner, U. S. Geol.
Survey Prof. Paper 142-A, p. 48, pl. 12,
figs, 5, 6 (ex parte).
The material on which this species was based was un-
fortunately juvenile. I did not recognize this at the time.
The species was fairly common and well distributed through
the Shoal River formation and there were no large shells
associated with the small nicholsi in which I did not notice
any signs of immaturity. In the later collections from
White's Creek, particularly in those made by the Florida
Survey, there are pectens bearing slight resemblance to those
described and figured under nicholsi but which are apparent-
ly the adults of forms subspecifically related to that species.
These larger shells are not typical of any described section
of Chlamys. They are more inflated than those of typical
Chlamys; the ribs do not increase by intercalation with the
growth of the shell and are too narrow and high and sharply
defined for typical Aequipecten although the species may pos-
sibly be referable to that section. The secondary threading
developed upon the costal and intercostal areas in the adults
throws the form out of Plagioctenium in which it was first





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 17

placed. The shell is relatively high and small for Lyropecten
and much less coarse than typical shells of that section; the
ribs are more numerous, and the ears too small, but the gen-
eral character of the sculpture is typical for Lyropecten to
which it is referred with grave doubts. The adult shell is
herewith described.
Shell of moderate dimensions, relatively high, somewhat
produced posteriorly, the left valve inflated, the right valve
less strongly convex. Umbonal angle a little more than 90.
Anterior dorsal margins short, the posterior obliquely pro-
duced. Ventral arc including more than 1800. Radials 22
in number in the right valve, 21 in the left of another indi-
vidual, narrow, high and spreading scarcely at all at the
ventral margin. Intercostals U-shaped with straight sides
and about the same width as the costals. Secondary thread-
ing developed near the close of the adolescent stage though
there is a wide variation in the time of appearance of the
secondaries but a marked uniformity in the character when
once established. Secondaries 3 in number on each of the
primaries, a medial secondary and occasionally secondaries
on either side in each of the intercostal channels and feeble
lirations upon the sides of the costals. Submargins smooth in
the juvenile stages, lirate in the adult, the inner lirae increas-
ing in prominence in the adolescent stages and developing in-
to primary ribs, thereby increasing the number of the cos-
tals. Incremental grating fine and sharp, much more crowd-
ed in some individuals than in others. Auricles rather small.
Byssal notch relatively deeper in the young than in the adults;
threading upon the byssal ear rather coarse and irregular,
imbricated by the incrementals. Lirae upon the posterior
right auricle and the anterior and posterior left auricles less
coarse and more numerous. Ctenolium distinct. Length of
hinge line slightly less than half the maximum width of the
shell. Ligament area very narrow, persisting almost to the
distal extremities of the hinge. Ligament pit small, trigonal,
subumbonal. Cardinal crura ill defined. Monomyarian, the
single muscle adductor scar obscure. Inner surface and ven-
tral margin fluted in harmony with the external ribbing.
Dimensions of cotypes: Right valve, height 59.0 milli-
meters; width, 56.5 millimeters; thickness, 12.0 millimeters.





18 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Left valve of another individual, height 59.0 millimeters;
width, 55.3 millimeters; thickness, 13.8 millimeters.
Type material: Two cotypes, a right and a left valve of
two different individuals, U. S. Nat. Mus. No. 372893.
Type locality: U. S. G. S. Sta. No. 10603, gully south of
the road and east of the bridge over White's Creek, on road
from Eucheeanna to Knox Hill, 6.7 miles south of Argyle,
1.7 miles southeast of Eucheeanna, Walton County, Florida.
Shoal River formation of the Alum Bluff group.
The young of the subspecies are very difficult to separate
from the peripheral forms of nicholsi sensu strict. It is un-
fortunate that there is no adult material from Shell Bluff and
the other Shoal River localities northwest of Mossyhead.
These are slightly older than the White's Creek outcrops and
there are probably time differences involved in the variations
in the faunas.
Some of the differences implied in the descriptions and
figures of Chlamys nicholsi and neotera are merely differ-
ences due to the age of the individual. The young are rela-
tively broader than the adults, the ribs are more numerous
by 1 or 2, and possibly more, in the adult than in the young;
there is no indication of the adult secondary radial sculpture
in the young on either the disk or the submargins and the
adult auricles are relatively smaller and higher, and the
byssal notch not so deep. There are certain differences, how-
ever, which can not be related to the age of the shell. The
ribs of the White's Creek species are usually more numerous
by 2 or more even in the young forms and they are consistent-
ly more angular. Specimens from the upper part of the
Shoal River, 3/2 miles southwest of DeFuniak Springs
measuring more than 30.0 millimeters in height show no
trace of secondary ribbing on either the disk or the sub-
margins. On the White's Creek individuals the liration usu-
ally makes its abrupt appearance at the close of a pronounced
resting stage when the shell is between 20.0 and 30.0 milli-
meters in height. The relationship between the individuals
from Shell Bluff with 17 smooth rounded ribs and that from
White's Creek with 21 lirate squarish ribs is still somewhat
obscure but it is certainly closer than one might infer from
the figured material.





ADDITIONS TO MOLLUSCAN FAINA ALUM BLUFF GROUP 19

Distribution: Shoal River formation, localities 9957c,
10603a, 10608P and in the collections made by the State Geolog-
ical Survey of Florida.
Chlamys (Nodipecten) pyx Gardner, new species
Plate 1, Figures 7-9
Shell of moderate dimensions, rather heavy, inequivalve, in-
equilateral, obliquely produced posteriorly but not to a mark-
ed degree. Right valve more inflated than the left and with a
conspicuously different sculpture pattern. Apical angle close
to 900, the ventral margin approximating the quadrant of a
circle. Tips of the umbones of both valves sculptured with 15
or 16 subequal and equispaced radials. Major ribs usually four
in number in the right valve, the two lateral ribs less sharply
defined than the two in the middle, each of them including
3 or 4 of the subequal umbonal ribs, which become more or
less obscure and sometimes obsolete toward the margin. In-
terradials very deep U-shaped channels with vertical walls
finely grated by the incrementals; a radial threading also
developed toward the ventral margin both in the costal and
the intercostal areas. Sculpture of the left valve the reverse
of that of the right, the costals high and narrow, represent-
ing a single umbonal rib, the intercostals two or three times
as wide and rather shallow, in which the intermediate um-
bonal ribs persist but with no uniformity in prominence; sec-
ondary threading developed upon the left valve similar to that
upon the right. Intermittent knuckling best developed upon
the left valve though there are no hollow bullae as in the
typical Nodipecten. Submargins steep wide and smooth.
Auricles small. Byssal groove not very wide, incrementally
striated. Right anterior auricle threaded with 6 and an ob-
scure seventh radial leaving a narrow, smooth wedge-
shaped area along the dorsal margin; right posterior
auricle with narrow sharper threads 10 in number on the
type and a smooth marginal area. Left auricles sharply
threaded, the number of radial threads increasing by inter-
calation to about 10 toward the lateral margin. Ctenolium
rather coarse, distinct. Ligament grooves narrow, shallow-
ed and obscured by weathering. Resilial pit small, trigonal.
Cardinal crura indicated but not developed with any degree
of uniformity. Outline of muscle scars not traceable. In-





20 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

terior of shell rippled in harmony with the major external
ribbing. Crenae of inner margins reflecting the umbonal
ribbing.
Dimensions of cotypes: Right valve, height, 53.5 milli-
meters; width, 56.1 millimeters; thickness, 18.5 millimeters.
Left valve of another individual, height, 46.4 millimeters;
width, 47.0 millimeters; thickness, 12.5 millimeters.
Type material: Two cotypes, a right and a left valve
not of the same individual, and one juvenile paratype, U. S.
Nat. Mus. No. 372894.
Type locality: U. S. G. S. Sta. No. 10603, gully south of
the road and east of the bridge over White's Creek, on road
from Eucheeanna to Knox Hill, 6.7 miles south of Argyle,
1.7 miles southeast of Eucheeanna, Walton County, Florida.
Shoal River formation of the Alum Bluff group.
Chlamys (Nodipecten) pyx stands apart from any of the
described Tertiary or Recent species in the dissimilarity of
the sculpture upon the two valves and in the width and prom-
inence of the few ribs upon the right valve. A single im-
perfect valve, probably a left, from the type locality, but
from an earlier collection, is apparently N. condylomatus
Dall, a Chipola species. Associated with it were juveniles
which could not be determined until these later White's Creek
collections had been made. Nodipecten pyx, the only other
Nodipecten recognized in the Shoal River, is fairly common
both in the collection No. 10603 and that made from the same
locality by the State Geological Survey of Florida. The
preservation is not very good, particularly of the adult right
valves and much of the sculpture detail has been lost. The
juveniles, on the other hand, are perfectly preserved.
The only possibility of confusion with any other describ-
ed species is that of the left juveniles with those of N. condy-
lomatus. The sculpture of the Chipola species is more uni-
form, and the secondaries are usually grooved medially.
Distribution: Shoal River formation, locality 10603'.
Astarte (Ashtarotha) species
Plate 4, Figure 1
A worn right valve of Astarte (Ashtarotha) submitted
by the Florida Geological Survey is our first record of this
typically cold-water genus in the Chipola of Florida. The





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 21

species is probably undescribed but related to the Choctaw-
hatchee forms rather than to those from the later Alum
Bluff. The shell is compressed, ovate-trigonal and slightly
warped posteriorly. The umbonal angle is not far from 60 ;
the tips are bent inward and forward over the rather
large lunule. The escutcheon is lanceolate. The sculpture is
restricted to a few ripples upon the umbones and to faint in-
cremental striae. The cardinal area is high and laterally
compressed and bent forward with the inclination of the
beaks. There are no laterals and the other characters of the
interior are obscured by weathering.
Dimensions: Right valve, height, 14.6 millimeters; width,
16.2 millimeters; thickness, 4.0 millimeters.
Figured specimen: U. S. Nat. Mus. No. 372892.
Locality: One-fourth mile below Bailey's Ferry, Chi-
pola River, Calhoun County, Florida. Chipola formation of
the Alum Bluff group.
This single right valve is of uncommon interest since it
is the first record of which I am aware of the Ashtarotha so
abundant and diversified in the Chesapeake group and the
Choctawhatchee. It is apparently more closely related to the
type of the section than any forms recovered from the later
Oak Grove or Shoal River.
Astarte (Bythiamena) wagneri Dall
The recurrence in considerable abundance of the Oak
Grove species Astarte wagneri in the late Shoal River faunas
was not to be expected. The species is variable in the White's
Creek fauna; in some individuals, the rippling is restricted to
the umbonal region, in others it is strong and uniform over
the entire disk and there is a complete series of intermediate
forms. Possibly, there was a slight change in temperature
conditions at the close of the Shoal River so that certain con-
trolling ecological factors more closely approximated the Oak
Grove conditions and permitted the return of the Astarte,
a group commonly associated with the cooler waters. The
same controls may possibly account for the Crassatellites
(Crassinella) tanicus Dall of the White's Creek fauna which
more closely resembles in its mutations those of the Oak
Grove than those of the Shell Bluff faunas.





22 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Distribution: Shoal River formation, localities 10603",
10608c.
Crassatellites (Scambula) densus Dall
Plate 3, Figure 1; Plate 4, Figures 2-5
The series of Crassatellites (Scambula) of which densus
is a well represented member includes a number of sensitive
types with a restricted stratigraphic range. There are cer-
tain differences which would be discernible in a composite of
the White's Creek densus and that from Shell Bluff but it
does not seem profitable to attempt to recognize them taxo-
nomically. The average inflation is probably lower in the
White's Creek forms and the tilt of the tips of the umbones
not so marked. This is interesting because the White's
Creek form is thus brought closer to C. meridionalis sensu
lato, from the Choctawhatchee. There is a considerable
variation, also, in the degree of warping of the ventral mar-
gin which in certain individuals is very broadly and evenly
curved, in others, quite strongly constricted in front of the
keel. The figures well illustrate the variation in the develop-
ment of the concentric sculpture, which in some individuals is
restricted to the anterior portion of the shell, in others is so
strong and so regular that the surface resembles that of
Crassatellites gibbesii, and in others is absent altogether ex-
cepting in the umbonal area.
This species is particularly abundant at White's Creek.
Distribution: Shoal River formation, localities 10603",
10608c.
Crassatellites (Crassinella) tanicus Dall
In the discussion of the Crassinellas in 19267 certain
individuals from an early collection (9957) were referred
questionably to the Chipola species triangulatus Dall because
of the strong development of the concentric sculpture. Sim-
ilar individuals are not uncommon in the later collections
from White's Creek but they probably represent a varietal
form of tanicus rather than that of triangulatus. The C. lunu-
latus of the Choctawhatchee develops a sculpture reminiscent
of C. triangulatus but stronger and more uniform over the en-
7Gardner, Julia, Molluscan fauna of the Alum Bluff group of
Florida: U. S. Geol. Survey Prof. Paper 142-B, Pt. 2, pp. 86, 87, 1926.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 23

tire disk, and like that of triangulatus, it is sharp and raspy
rather than rippled as in C. tanicus. In the strongly sculp-
tured variants of C. tanicus the ripples are persistent in some
individuals to the ventral margin but they are very rarely
pinched into sharp lamellae. There is no obvious reason
to suppose that these more highly adorned White's Creek
forms are genetically related to the succeeding C. lunulatus,
rather than to C. tanicus, and there is little to be gained by ac-
cording them recognition in the taxonomy. The sculptured
variants are curiously enough less rare in the Oak Grove
faunas than in those from the Shell Bluff horizon of the
Shoal River.
Venericardia (Megacardita) hesperide Gardner, new species
Plate 5, Figures 16, 17
Shell large for the genus, heavy and coarsely sculptured,
rudely quadrate in the interior view, obliquely elongated in
the exterior. Dorsal and ventral margins subparallel, the
anterior lateral margin rounding broadly into the base; pos-
terior lateral margin imperfect but probably obscurely
truncate. Posterior area indicated by a change in the con-
touring and sculpture. Umbones near the anterior extremity,
full, prominent, involute and prosogyrate. Lunule small but
deep and very distinct and defined by a sharply incised line.
Ornamentation coarse. Ribs 20 in all, 12 in number from
the foremost to that outlining the anterior margin of the keel,
2 less prominent upon the keel and 6 much smaller and lower
ribs upon the slightly concave posterior area; anterior and
medial ribs broadly arched, separated by deep-set grooves;
incremental wrinkling very marked, especially toward the
anterior and ventral margins. Ligament groove deep, ex-
tended, opisthodetic. Hinge worn; right medial cardinal
heavy and obliquely elongated; posterior cardinal laminar
and much produced; anterior cardinal either very small or
atrophied. Left valve not known. Adductor muscle scars
large, a smaller scar, probably the pedal, just within the an-
terior margin between the lunular groove and the anterior ad-
ductor scar. Pallial line simple, obscure. Inner margins
coarsely crenate.
Dimensions of holotype, right valve: Height, 47.0 milli-
meters; width, 53.0 millimeters; thickness, 19.7 millimeters.
Type material: Holotype, U. S. Nat. Mus. No. 372890.






24 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Type locality: Collected by the State Geological Survey
of Florida in a gully on the east side of White's Creek, 200
feet south of the bridge on the road to Knox Hill, 6.7 miles
by road south of Argyle and about 1.7 miles southeast of
Eucheeanna, Walton County, Florida. Shoal River forma-
tion of the Alum Bluff group.
The type, a right valve, is unique, but it is of interest
because it represents more closely than any other described
specimen from the Miocene deposits of the Seaboard and the
Gulf the Megacardita group of the European Miocene. In
fact, it bears a strong superficial resemblance to the type of
Sacco's subgenus, Megacardita Joiuanneti (Basterot), so
abundant in the South European deposits. According to Coss-
mann the "Couches a Cardita Jouanneti" "stigmatize" the
middle Miocene as Venericardia planicosla "stigmatizes"
the Eocene, and the presence of a species so closely allied in
our own middle Miocene may be of some significance. The
American species is not so thick-shelled as the most of the
European specimens, the inflation is greater, the umbones
are fuller, the ribs are higher and possibly fewer by one or
two, and the margin of the lunule is more expanded. There
are no related forms in the American faunas. Venericardia
hadra of the Chipola and V. himerta of the Oak Grove are
possibly in the ancestral line but they are much higher with
more narrow ribs more distantly spaced. There are also
marked differences in the dentition of the Shoal River form
and those from the lower formations. Nothing of the kind
has been reported from the Gatun or Santo Domingan faunas,
so that for the present, this single right valve is the sole
American representative of an exceedingly prolific and
stratigraphically important south European group.
Distribution: Shoal River formation, White's Creek, 200
feet south of the bridge on the road to Knox Hill, 6.7 miles
by road south of Argyle and about 1.7 miles southeast of
Eucheeanna, Walton County, Florida.
Venericardia (Pleuromeris) aposcitula Gardner, new species
Plate 5, Figures 1, 4
Shell small, trigonal-ovate, inflated, moderately heavy.
Umbones medial or submedial. Anterior extremity broadly
and evenly rounded; posterior dorsal margin obscurely trun-





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 25

cate, posterior lateral margin rounding smoothly into the up-
curved base. Lunule and escutcheon smooth, inconspicuous
but clearly defined, the escutcheon lanceolate and very nar-
row, the lunule cordate. Prodissoconch minute, unsculptured
excepting for a few incremental striae. Conch adorned with
narrow, noded, sharply elevated radials, 13 in number on the
cotypes, radiating fanlike from the tips of the umbones and
persisting to the ventral margin which they sharply crenu-
late. Incremental striations best defined toward the ventral
margin, and at the intersections with the costals. Ligament
external, opisthodetic. Dentition delicate for so sturdy a
shell. Middle cardinal of right valve, heavy, broadly trigonal,
the anterior and posterior cardinals short and laminar; left
anterior cardinal fairly heavy, the posterior more produced
and more slender. Muscle and pedal scars distinct and rela-
tively large for so small a shell. Pallial line simple, rela-
tively distant from the crenate ventral margin.
Dimensions of cotypes: Right valve, height and width,
3.0 millimeters; thickness, 1.5 millimeters. Left valve of
another individual, height, 3.1 millimeters; width, 3.3 milli-
meters; thickness, 1.4 millimeters.
Type material: Two cotypes, the right and the left valves
of 2 individuals, U. S. Nat. Mus. No. 372901.
Type locality: Collected by the State Geological Survey
of Florida. Gully on east side of White's Creek, 200 feet
south of the bridge on the road to Knox Hill, 6.7 miles south
of Argyle and 1.7 miles southeast of Eucheeanna, Walton
County, Florida. Shoal River formation of the Alum Bluff
group.
Venericardia aposcitula is best separated from the Oak
Grove V. scitula by the relatively higher, sharper and more
narrow ribs. The number is about the same in the two
species, from 12 to 16 in scitula, from 13 to 15 in observed
individuals of aposcitula. V. aposcitula is the more delicate
shell and the umbonal angle is less acute than in the Oak
Grove form. The Chipola species V. tellia is a heavier shell
with heavier ribbing and dentition.
To Venericardia aposcitula are referred the "closely
allied forms imperfectly, preserved. in the Shoal River forma-




26 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

tion" cited under the discussion of V. scitula in 19268.
Distribution: Shoal River formation, localities 9958r,
9959r, 10603P, 10608P.
Phacoides (Parvilucina) diktyota Gardner, new species
Plate 5, Figures 2, 3
Shell small but heavy, globose, subequilateral. Umbones
full even to the minute, submedial and proximate tips. Dor-
sal margins gently inclined, the lateral margins obscurely
truncate vertically and rounding into the strongly curved
base. A rather large posterior area indicated by an obtuse
keel and the absence of radial sculpture. Lunule large, sun-
ken, sharply defined by the depressed contour and by the
abrupt cessation of the sculpture both radial and concentric.
Escutcheon also smooth, narrow, lanceolate, slightly less pro-
duced than the lunule. Tips of the umbones evenly threaded
with fine sharp concentric lirae. Radial sculpture introduced
when the shell is between 2 and 3 millimeters high, developing
into a fine even threading covering the disk from the poster-
ior area to the anterior but evanescing toward the ventral
margin; concentric lirae sharper than the radial and over-
riding them, continuous from the lunule to the escutcheon
but less strong toward the lateral margins, and much crowd-
ed ventrally. Ligament groove short, deeply inset along the
posterior dorsal margin. Dentition rather heavy for so small
a shell. Anterior cardinal atrophied, the posterior, a short
subumbonal hook. Laterals, both anterior and posterior ex-
ceptionally well developed. Characters of the interior ob-
scure. Anterior muscle scar very short and broad for the
group, the posterior smaller and more circular in outline.
Pallial line distinct, simple, remote from the margin. Mar-
ginal crenations short but strong.
Dimensions of holotype, right valve: Height, 4.0 milli-
meters; width, 4.0 millimeters; thickness, 2.0 millimeters.
Type material: Holotype, a right valve, U. S. Nat. Mus.
No. 372906.
Type locality: U. S. G. S. Sta. No. 10603, gully south of
the road and east of the bridge over White's Creek, on road
from Eucheeanna to Knox Hill, 6.7 miles south of Argyle, 1.7
"Gardner, Julia, The mollhs 'qi faun-'of the Alum Bluff group
of Florida: U. S. Geol. Survey '.rof. Paper 1.42.:, Pt. II, Astartacea,
Carditacea, Chamioca, p. 91, 1926.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 27

miles southeast of Eucheeanna, Walton County, Florida.
Shoal River formation of the Alum Bluff group.
The type is unique excepting for a single other badly erod-
ed and questionable valve.
It has been named with some hesitation but it is excep-
tionally well characterized among the Parvilucinas by the
globose form, well defined posterior area, sharply reticulate
sculpture and strong dentition. The closest kinship is proba-
bly with the P. multilineata group.
Distribution: Shoal River formation, localities 10603r,
10608 F.
Phacoides (Callucina) cala Gardner, new species
Plate 4, Figures 6-9
Shell of moderate dimensions, rather thin for the group,
moderately inflated, transversely oval in outline. Umbones
acute, proximate and prosogyrate at the tips, slightly poster-
ior, not conspicuous. Shell constricted in front of the um-
bones; posterior dorsal margin feebly and obliquely arcuate;
curvature of lateral and basal margins very low. Lunule
small but deeply impressed, wider in the right valve than
in the left. Escutcheon not defined. Prodissoconch smooth
excepting for incremental striae, minute. Surface sculpture
of broad squarish ripples, fairly uniform in arrangement on
the umbones but becoming irregular and dying out away
from the umbones, usually persisting, however, on the an-
terior portion of the shell; concentric sculpture of narrow,
low, flat, not very uniform fillets, least feeble upon the in-
terradial channels, and of incremental striae with occasional
pronounced resting stages. Ligament inset in a deep groove
extending more than half the length of the posterior dorsal
margin. Anterior right cardinal merged with the lunular
margin, the posterior cardinal short, strong and deeply
grooved; left anterior and posterior cardinals short and
sturdy; rudimentary lateral teeth indicated in the right
valve, but no corresponding sockets developed in the left.
Interior of the shell thickened slightly over the area of the
adherent mantle. Anterior muscle scar narrow and much
produced, the posterior smaller and less distinct. Pallial
line simple, distinct. Interior faintly rayed, the margins
feebly crenate.





28 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Dimensions of cotypes: Right valve, height, 10.7 milli-
meters, width, 11.0 millimeters; thickness, 3.5 millimeters.
Left valve of another individual, height, 10.2 millimeters;
width, 10.7 millimeters; thickness, 3.5 millimeters.
Type material: Two cotypes, the right and left valves
of different individuals, U. S. Nat. Mus. No. 372904.
Type locality: U. S. G. S. Sta. No. 10603, gully south
oi' the road and east of the bridge over White's Creek, on
road from Eucheeanna to Knox Hill, 6.7 miles south of Ar-
gyle, 1.7 miles southeast of Eucheeanna, Walton County,
Florida. Shoal River formation, Alum Bluff group.
A species closely related to Phacoides (Callucina) cala
was indicated under Codakia (Jagonia) in the earlier col-
lections covered by the 1926 report' but there was no ade-
quate type material available at the time. The right cardinal
in Callucina is bifid; in Codakia (Jagonia), the analogous
tooth is simple and the laterals much more strongly develop-
ed in both the right and the left valves than they are in
Callucina. Codakia erosa Dall from the Chipola fauna is ap-
parently a worn Callucina and is a smaller, heavier shell than
C. cala, with a cruder ornamentation, both radial and concen-
tric. The White's Creek species runs much the same wide
range of variation in sculpture detail as that exhibited by the
Bellucina section of Phacoides, and in external aspect the two
groups may strongly resemble one another.
Distribution: Shoal River formation, localities 10603',
10608P, collections of the State Geological Survey of Florida.
Diplodonta (Phlyctiderma) (glos subsp.?) lampra Gardner,
new species
Plate 5, Figures 5-7
Shell small, very thin, polished without and within, with
subcircular margins and a moderately inflated disk. UTm-
bones medial or slightly posterior, rather full, not conspicu-
ous, with pointed orthogyrate proximate tips. Anterior por-
tion of the shell broadly and evenly arcuate, the posterior
flattening less gradually and the posterior dorsal margin
obscurely truncate; ventral margin a smooth arc. Outer sur-
face smooth excepting for incrementals least feeble anter-
"Gardner, Julia, The molluscan fauna of the Alum Bluff group
of Florida: i. 8. Geol. Survey Prof. Paper 142-C, p. 103, 1926.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 29

iorly and a very obscure and microscopically fine roughening
of the shell. Ligament deeply inset, marginal, opisthodetic.
Dentition delicate; a short simple laminar anterior cardinal
and a bifid posterior in the right valve and a bifid anterior
and short laminar posterior in the left. Adductor scars and
pallial line obscure. Inner surface faintly rayed. Inner
margins smooth.
Dimensions of cotypes: Right valve, height, 8.4 milli-
meters; width, 8.5 millimeters; thickness, 2.2 millimeters.
Left valve of another individual, height, 8.4 millimeters;
width, 8.6 millimeters; thickness, 2.1 millimeters.
Type material: Two cotypes, the right and left valves
of different individuals, U. S. Nat. IMus. No. 372903.
Type locality: U. S. G. S. Sta. No. 2646, Oak Grove,
Yellow River, Okaloosa County, Florida. Oak Grove sand
of the Alum Bluff group.
It is just possible that these forms may be the young of
Diplodonta glos but though the outline is the same, none of
the characteristic punctate sculpture of D. glos could be dis-
cerned. Furthermore, these shells do not have the aspect of
immaturity although they are little more than half as large
as glos. Diplodonta glos has been hitherto restricted in its
known distribution to the Chipola while lampra is known only
from the type locality at Oak Grove. The co-existent D. nu-
cleiformis is very much more inflated and D. radiata is un-
commonly well characterized by the lirate inner margins.
Distribution: Oak Grove sand, locality 2646'.
Transennella caryera Gardner, new species
Plate 5, Figures 8, 9
Shell small, not very heavy, moderately inflated, ovate-
trigonal in outline. Umbones evenly rounded, subcentral, the
tips bent inward and forward. Lunule relatively large, elong-
ate-cordate, outlined by a shallow sulcus. Escutcheon not de-
fined. Anterior end very slightly bowed in front of the
lunule, rounding smoothly into the upeurved base. Posterior
margin slightly hunched. Base line gently arcuate. Outer
surface incrementally striate, the sculpture least feeble and
irregular toward the distal and ventral margins. Ligament
marginal, rather short, opisthodetic. Hinge relatively heavy,
normal. Anterior and medial right cardinals laminar, their





30 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

inner faces flattened and proximate; the posterior right
cardinal more produced and elevated. Anterior and posterior
left cardinals simple and laminar, the medial left cardinal
trigonal and feebly bifid. Anterior left lateral short but
prominent, received in the short deep lateral socket on the
lunular margin of the right valve. Adductor scars rela-
tively large, the anterior distinct, the posterior polished but
rather obscure. Pallial sinus short, broad, steeply ascending.
Pallial line relatively distant from the margin. Tangential
grooves few in number, running at a very low angle to the
edge of the anterior and ventral margins.
Dimensions of holotype, right valve: Height, 4.6 milli-
meters; width, 5.2 millimeters; thickness, 1.7 millimeters.
Type material: Holotype, a right valve, U. S. Nat.
Mus. No. 372912.
Type locality: U. S. G. S. Sta. No. 10603, Gully south
of the road and east of the bridge over White's Creek, on
road from Eucheeanna to Knox Hill, 6.7 miles south of Ar-
gyle, 1.7 miles southeast of Eucheeanna, Walton County,
Florida. Shoal River formation of the Alum Bluff group.
This is the first record of Transennella in the Shoal River
formation.
The described species most closely related to T. caryera
is Transennella santarosana Dall from the Oak Grove. The
latter species is lower relatively, more regularly striate con-
centrically on the outer surface and with deeper tangential
grooves along the inner edges of the anterior and ventral
margins.
Distribution: Shoal River formation, localities 10603P,
10608'.
Callocardia (Agriopoma) calceola Gardner, new species
Plate 7, Figures 3, 4
Shell thin for the group, a deep, transversely elongated
scoop, broadly rounded behind, narrow and snout-like in
front. Umbones low but full, the tips bent forward and in-
ward, falling near the beginning of the anterior third of the
shell. Lunule long and rather wide, defined by an incised
line. Escutcheon not delimited but suggested by the flatten-
ing of the shell and the evanescence of the sculpture. Outer





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 31

surface crowded with raised concentric threads not uniform-
ly continuous from the anterior to the posterior margin but
tending to bifurcate and reunite. Ligament deeply inset,
produced for about half the length of the posterior dorsal
margin. Hinge normal, that of the left valve only known.
Hinge plate thin, sinuous; anterior and medial cardinals
coalescent, obliquely divergent beneath the tips of the um-
bones; posterior cardinal laminar, produced; anterior lateral,
a dentate process near the anterior extremity of the hinge-
plate. Muscle scars large but inconspicuous, particularly the
posterior. Pallial line distinct, rather close to the margin.
Pallial sinus very broad and shallow, the axis directed to-
ward the tips of the umbones. Inner margins simple.
Dimensions of holotype, left valve: Height, 41.0 milli-
meters; width, 54.0 millimeters; thickness, 16.0 millimeters.
Type material: Holotype, a left valve, U. S. Nat. Mus.
No. 372888.
Type locality: U. S. G. S. Sta. No. 10603, gully south of
the road and east of the bridge over White's Creek, on road
from Eucheeanna to Knox Hill, 6.7 miles south of Argyle,
1.7 miles southeast of Eucheeanna, Walton County, Florida.
Shoal River formation of the Alum Bluff group.
The type is unique. It differs from all the other Alum
Bluff Callocardias in the greater dimensions and relatively
greater width but resembles in general outline and dimen-
sions the type of the subgenus, Callocardia (Agriopoma)
texasiana Dall, a Recent species in the western Gulf of Mexico.
The Recent species, however, is broader and less produced an-
teriorly, the muscle scars are smaller and the pallial sinus is
much deeper and acutely pointed.
Distribution: Shoal River formation, locality 10603'.
Pitar (Hysteroconcha [Lamelliconcha]) cypta Gardner, new species
Plate 5, Figures 10-13
Shell small, heavy, ovate-trigonal in outline, with high
full umbones slightly posterior in position. Posterior dorsal
margin obliquely arcuate, the lateral margin obtusely trun-
cate parallel to the vertical axis. Anterior margin bowed
slightly at the lunule, the lateral margin obliquely produced
to meet the base line in a sharp curve. Ventral margin ap-
proximately horizontal. Lunule rather large, cordate, de-





32 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

fined by a feebly incised line and by the weakening but not
the disappearance of the concentric sculpture. Escutcheon
not differentiated. Entire outer surface heavily ribbed con-
centrically; ribs running about 3 to the millimeter in the um-
bonal region and about 2 toward the ventral margin; tabulat-
ed upon their outer surfaces, more or less undercut dorsally,
most crowded anteriorly, continuous across the disk but not
quite so wide posteriorly and standing out from the rest of
the shell as in Chione. Ligament groove deep, inset, extend-
ing about half the length of the posterior dorsal margin.
Dentition strong, concentrated, built up from a well de-
veloped hinge plate. The anterior right cardinal short and
laminar, the medial short and trigonal, their inner faces flat-
tened and proximate; posterior right cardinal laminar and
produced. Left anterior cardinal very short and thin uniting
dorsally with the trigonal medial cardinal; left posterior
cardinal laminar and produced. A high lateral socket in
the right valve to receive the short strong lateral of the left.
Characters of the interior distinct if the shell is not too
much weathered. Muscle scars relatively large. Pallial sinus
broad, slightly ascending, acutely rounded at its extremity
near an obscure medial thickening not sufficiently well de-
fined to be called a rib, which extends from the umbonal re-
gion almost to the base. Pallial line distinct rather far re-
moved from the simple but slightly thickened ventral margin.
Dimensions: Holotype, left valve, height, 12.3 milli-
meters; width, 13.2 millimeters; thickness, 5.2 millimeters.
Paratype, right valve (individual not fully mature), height,
7.7 millimeters; width, 8.0 millimeters; thickness, 2.9 milli-
meters. Paratype, left valve of immature individual, height,
5.5 millimeters; width, 6.3 millimeters; thickness, 2.1 milli-
meters.
Type material: Holotype, U. S. Nat. Mus. No. 372866,
and two paratypes, U. S. Nat. Mus. No. 372913.
Type locality: In a gully on the east side of White's
Creek, 200 feet south of the bridge on the road to Knox Hill,
6.7 miles by road south of Argyle and about 1.7 miles south-
east of Eucheeanna, Walton County, Florida. Collection
made by the State Geological Survey of Florida. Shoal River
formation of the Alum Bluff group.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 33

Pitar (Lamelliconcha) cypta is a species uncommonly
well characterized by its rather crude blunt outline and the
heavy tabulated ribbing. There is no described species with
which it can be confused. The only other member of the
group recorded from the Alum Bluff, Miss Maury's Chipola
species, has a very different outline and a distinct ornamenta-
tion.
Distribution: Shoal River formation, localities 10603r,
10608r, State Geological Survey of Florida.
Chione (Chione) oulotricha Gardner, new species
Plate 7, Figures 1, 2
Shell rather thin and delicate for the genus, transversely
ovate-trigonal, smooth in outline and evenly rounded from
the tips of the umbones to the ventral margin. Umbones
small, not prominent, bent inward and forward. Anterior
margin bowed in front of the lunule rounding smoothly into
the ventral margin. Posterior extremity obtusely truncate,
the posterior dorsal margin very slightly arched. Lunule
small, relatively wide, delimited by a deep sulcus, evenly
laminated, the lamellae in line with those which adorn the
disk. Escutcheon narrow, smooth in the umbonal region but.
toward the ventral margin, with growth lines carried across
it with increasing prominence. A rather well defined but
not conspicuous posterior area marked by a change in the
direction of the concentric lamellae and their lower eleva-
tion. Tips of the umbones sculptured with fine regularly
spaced concentric threads which become rather abruptly
more prominent and on the disk appear as prominent evenly
spaced lamellae, evenly crinkled along the base of the outer
surface but smoothly corded along the upper edge; micros-
copically fine wavy lines between the lamellae; lamellae per-
sisting with uniform elevation across the disk the half of them
disappearing a short distance in front of the lunular and
anterior margins, the other half expanding and flaring out-
ward; lamellae continuous in unlessened numbers across the
posterior area but consistently lower and bending toward
the umbones, the change in direction becoming increasingly
prominent toward the umbones. Ligament external, thie area
of attachment narrow. Hinge plate delicate, sinuous. Three
cardinal teeth in the right valve, the opposing faces of the





34 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

anterior and medial teeth rounded as if to receive the com-
pressed but anteriorly flexed cardinal of the left valve; pos-
terior cardinal obliquely produced to the margin of the hinge
plate separated from the medial cardinal by a rather wide
deltoid socket. Muscle scars rather large, not conspicuous.
Pallial line and sinus easily traceable, the pallial line unusu-
ally distant from the margin. Pallial sinus short, broad,
linguiform, the projected axis cutting the dorsal margin at
the lunule. Inner margin very finely crenate from the tips of
the umbones along the lunular margin and the anterior and
ventral margins to the posterior margin which is smooth
within.
Dimensions of the holotype, right valve: Height, 28.4
millimeters; width, 36.2 millimeters; thickness, 10.3 milli-
meters.
Type material: Holotype, a right valve, U. S. Nat. Mus.
No. 372863.
Type locality: Ten Mile Creek, Chipola River, Calhoun
County, Florida. Chipola formation of the Alum Bluff group.
Chione oulotricha may well be in the direct ancestral line
to the late Miocene Chione cribaria Conrad, which it closely
resembles in sculpture and dentition.
Distribution: Chipola formation, Ten Mile Creek, Cal-
houn county, Florida. Collected by the State Geological Sur-
vey of Florida.
Chione (Lirophora) crossota Gardner, new species
Plate 7, Figure 8
Shell of moderate dimensions, not very heavy, transversely
ovate-trigonal. Umbones bent inward and forward near the
anterior third of the shell. Anterior lateral margin strongly
bowed in front of the lunule, the posterior obliquely truncate,
the ventral broadly curved. Lunule wider in the right valve
than in the left, impressed, sharply delimited. Escutcheon
lanceolate, defined by the contour of the shell and the abrupt
disappearance of the concentric lamellae. Initial shell com-
pressed, trigonal, sculptured only with a few (2 to 4) thin
sharp lamellae and between them faint, very fine, concentric
striae; heavy concentric ribbing abruptly initiated and, sim-
ultaneously, an irregular radial striation on the ventral sur-
face of the ribs; number of closed ribs variable (4 in the type)





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 35

giving place to upstanding flanges frilled at the base, more
or less recurved dorsally but thin-edged, persistent from di-
rectly behind the lunule to the posterior area where they
abruptly narrow and instead of being thin, high and upstand-
ing become rather narrow heavy lamellae directed outward
at a low angle and, at the edge of the escutcheon abruptly
disappear; faint concentric scratches in all the intercostal
areas. Ligament attachment area narrow, slightly more pro-
duced than the posterior cardinal. Hinge normal for the
genus and the sub-genus; right valve dentition including a
thin anterior, a moderately heavy deltoid medial and an
elongated posterior cardinal; left cardinals radiating fan-like
beneath the tips of the umbones, the medial the heaviest, the
posterior the most produced; right posterior dorsal margin
grooved a little to receive the edge of the left valve. Adductor
scars and pallial line distinct. Pallial sinus short, angular.
Inner lunular, anterior and ventral margins finely crenate.
Dimensions of holotype, right valve; Height, 25.0 milli-
meters; width, 33.8 millimeters; thickness, 11.0 millimeters.
Type material: Holotype, a right valve, U. S. Nat. Mus.
No. 372865.
Type locality: U. S. G. S. Sta. No. 10603, Gully south of
the road and east of the bridge over White's Creek, on road
from Eucheeanna to Knox Hill, 6.7 miles south of Argyle,
1.7 miles southeast of Eucheeanna, Walton County, Florida.
Shoal River formation of the Alum Bluff group.
Chione crossota is an end member of the group of C. cera-
mota and C. ulocyma Dall and the peripheral forms can not
be separated with assurance. The type of C. crossota is, how-
ever, quite distinct from the type of C. ceramota. It is a
smaller lighter shell, lower and relatively more transversely
elongate with fewer, higher, free-edged ribs. Typical forms
are not abundant but gradational individuals are very com-
mon. Additional subspecies might be made but there is little
to be gained by increasing the names. The limitations of
paleontology are realized in trying to interpret such a series.
According to the latest concepts two closely related forms
do not occupy exactly the same habitat but there are many
different factors such as slight differences in the salinity
or food supply or other animal life which would leave no





36 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

trace in the fossil fauna. In any case, there seem to be in
the White's Creek fauna at least four species occurring in
greater or less abundance and grading and intergrading;
Chione trimeris, the largest and coarsest of them all with
more or less fused ribs; Chione funiakensis also with fused
ribs, a rather persistent radial sculpture, and a rather thin
shell; Chione ceramota, short and high with numerous ribs
not fused but bent back and almost or quite touching the shell
at the dorsal edge of the rib; and Chione crossota with a few
high free ribs and a relatively light transversely elongate
shell.
Distribution: Shoal River formation, locality 10603P.
Chione (Lirophora) cymaina Gardner, new species
Plate 5, Figures 14, 15
Shell rather large for the group, massive, trigonal. Ulm-
bones small, high, flattened and pointed forward. Anterior
margin strongly bowed in front of the lunule, rounding
smoothly into the base. Posterior margin obliquely truncate
from the beaks to the base. Lunule large, cordate, defined by
a sulcus, scooped out, and the flattened area directly in front
of the umbones obscurely defined, in effect a lunule within a
lunule, the entire area corrugated by the strong growth lines.
Escutcheon wide, sharply delimited, smoother than the lunule,
the growth lines only faintly traceable upon it. Tips of um-
bones sculptured only with faint concentric lines and a few
not very sharp nor prominent overlapping lamellae, the first
heavy billowy concentric rib initiated when the shell is less
than half a millimeter high. Adult sculpture of relatively
few-about half a dozen-very prominent, crude and irregu-
lar ribs, scratched on the dorsal concave surface of the ribs
with irregularly spaced concentric lines and, on the ventral
surface, rather faintly and irregularly lineated radially. Lig-
ament external, the area of attachment adequate. Dentition
strong and normal. Anterior cardinal of right valve laminar
and crowded by the lunular margin, not persisting to the
margin of the hinge plate, the medial cardinal feebly bifid
upon its dorsal surface, the posterior cardinal produced from
the umbones to the wavy margin of the hinge plate. Cardinals
of the left valve also three in number, more uniform in size
than those of the right, the anterior thinner, however, than





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 37

those behind it and the posterior the most produced; a rein-
forcement at the base of the teeth near the umbones especial-
ly between the posterior and medial teeth. Interior slightly
thickened over the area of the adherent mantle. Pallial scars
distinct. Pallial line and sinus usually traceable, the sinus
short and angular, the apex of the angle pointed forward and
upward. Inner margins very finely crenate from the tips
of the umbones around the lunule, the anterior and ventral
margins to the edge of the escutcheon.
Dimensions of cotypes: Right valve, height, 32.3 milli-
meters; width, 39.1 millimeters; thickness, 12.8 millimeters.
Left valve, height, 33.0 millimeters; width, 35.0 millimeters;
thickness, 12.3 millimeters.
Type material: Two cotypes, a right and a left valve not
of the same individual, U. S. Nat. Mus. No. 372862.
Type locality: Collected by the State Geological Survey
of Florida. In a gully on the east side of White's Creek, 200
feet south of the bridge on the road to Knox Hill, 6.7 miles
by road south of Argyle and about 1.7 miles southeast of
Eucheeanna, Walton County, Florida. Shoal River forma-
tion of the Alum Bluff group.
Chione (Lirophora) cymaina is well characterized. There
is no other species in the Alum Bluff that has such heavy ribs
and none in which the ribs approach so closely to the escut-
cheon. The species may be a progenitor of the later Miocene
species, Chione latilirata Conrad, the type of the subgenus
Lirophora.
Distribution: Shoal River formation, locality 9957P and
State Geological Survey of Florida.
Chione (Lirophora) species
A very large undescribed species of Chione (Lirophora)
is indicated in the limestone at Lake Butler, Bradford Coun-
ty. The shell is not preserved but the molds are some of them
more than 40 millimeters in height and more than 65 milli-
meters in width. The ribs are very heavy and, exclusive of
those upon the umbones, are 4 to 6 in number. They do not
coalesce but pinch out abruptly a little in front of the poster-
ior keel as in Chione glyptocyma Dall and in most of the
Chione (Lirophora) from the Shoal River. In Chione sel-





38 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

lardsi, however, and in Chione cymaina, the heavy ribs merely
break down into the component lamellae. In general dimen-
sions, this Chione far outstrips any of the described Alum
Bluff species but the description must await better material.
Petricola? senterfeiti Gardner, new species
Plate 6, Figures 1, 2
Shell moderately thin and convex, transversely ovate to
subquadrate, gaping posteriorly; anterior end broadly round-
ed, the posterior warped and truncate, the ventral margin
nearly horizontal, incurved. Umbones near the anterior third,
not very prominent, incrementally sculptured, bearing on
their prosogyrate tips the minute ovate trigonal prodisso-
conch. No lunule, escutcheon or posterior area differentiat-
ed. Sculpture reduced to incrementals with occasional rest-
ing stages and to a faint lateral threading or wrinkling per-
ceptible in one shell near the posterior margin only, on the
other near the anterior as well. Ligament external, opistho-
detic, the groove deep and the nymph strong. Dentition
reduced in the left valve to 2 divergent rudimentary teeth
and between them and linked with the anterior, a third rudi-
mentary tubercle, all of them mounted upon the reversed
dorsal edge of the valve. Interior surface warped and ir-
regular. Adductor scars fairly distinct, the subcircular to
semi-elliptical posterior more so than the pyriform anterior.
Pallial sinus very broad and deep, the ragged truncated
lateral margin in line with the tips of the umbones, the
ventral margin not confluent with the obscure and remote
pallial line.
Dimensions of holotype, left valve: Height, 13.0 millime-
ters; width, 17.5 millimeters; thickness, 4.3 millimeters.
Type material: Holotype, a left valve, U. S. Nat. Mus. No.
372909; paratype, U. S. Nat. Mus. No. 372914.
Type locality: Senterfeit Branch, 4 miles southwest of
Laurel Hill, Okaloosa County, Florida. Collected by the State
Geological Survey of Florida. Oak Grove sand? of the Alum
Bluff group.
The species is known only from the holotype and the
paratype.
Both valves are to a certain extent warped by their situs.




ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 39

Distribution: Oak Grove sand?, Senterfeit Branch, 4 miles
southwest of Laurel Hill, Okaloosa County, Florida. Col-
lected by the State Geological Survey of Florida.
Pleiorytis Conrad
Pleiorytis, Conrad, Acad. Nat. Sci. Philadelphia Proc. for
1862, p. 286, 1862.
"Equivalve, ovate or oval, with radiating striae, gaping
posteriorly; hinge of right valve with two widely diverging
teeth; left valve with one direct thick triangular, bifid tooth
under the apex, and an oblique compressed tooth posterior-
ly; sinus of pallial impression extending beyond the middle
of the valves; muscular impressions large. (Miocene.)"
Conrad, 1862.
Monotype: Pleiorytis ovata Conrad (Day's Point, James
River, Virginia)=Petricola centenaria Conrad, 1833. (P1. 6,
figs. 3, 4.)
Conrad placed this genus under the family Petricolidae.
The group of Pleiorytis centenaria Conrad has a limited
geographic and stratigraphic range and perhaps for that
reason its dissimilarity to the type of Asaphis, (Venus de-
florata Linnaeus from the Bahamas, pl. 6, figs. 6, 7) has ap-
parently not been noticed. In Asaphis, as in many of the tel-
linids, the tips of the umbones are bent inward and very
slightly backward and there is no trace of a lunular spur
across the cardinals. In Pleiorytis, as in Petricola and other
venerids, the umbones are decidedly prosogyrate and the
lunular spur is more or less developed. In Asaphis, the bifid
cardinal of the right valve is produced and oblique; in
Pleiorytis it is short and nearly vertical. In Asaphis in the
left valve the dorsal margin is tabulated in front of the bifid
cardinal; in Pleiorytis there is a well developed laminar, left
anterior cardinal.
The general relationships of Pleiorytis were properly in-
dicated by Conrad, and though possibly it should be given
only subgeneric rank under Petricola, the habits of the animal
are not that of typical Petricola, the shell is not adjusted to
a boring situs and the consequent differences may be rec-
ognized generically. The genus may then be described as
follows:





40 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Shell of moderate dimensions, rather thin, slightly gaping;
transversely elongate, moderately inflated. Umbones an-
terior, not conspicuously prominent, the tips proximate and
prosogyrate. Lunule and escutcheon not developed. Pos-
terior area flattened but not rostrate. Ligament strong, ex-
ternal. A slender spur from the lunular region carried across
the cardinals. Teeth short, built up from a narrow hinge
plate; a laminar anterior and bifid medial cardinal in the
right valve, the posterior cardinal almost or entirely obso-
lete; a laminar anterior, bifid medial and laminar posterior
cardinal in the left valve. Laterals not developed. Adduc-
tor scars large, the pallial sinus broad and deep, not con-
fluent ventrally with the pallial line. Inner edges of the
valves simple.
The group is particularly characteristic of the middle and
upper Miocene of the Eastern seaboard of the United States.
Petricola (Rupellaria) harrisii Dall has a hinge identical
with that of Pleiorytis centenaria and may, as indicated by
W. C. Mansfield,o1 be nothing more than a much warped in-
dividual of that species. Warping is not common in the group
but it is present to a very considerable degree in a few in-
dividuals. Petricola (Petricolaria) calvertensis Dall is
similar in sculpture but is more cylindrical and though the
hinge is rather badly broken it does not seem to have the
hinge plate so well developed as that of Pleiorytis.
Pleiorytis bowenae Gardner, new species
Plate 6, Figures 5, 8, 9
Shell rather small and thin for the group, transversely
elliptical in outline, slightly gaping, moderately inflated. Um-
bones fairly high for the group, not very full, the tips proxi-
mate and prosogyrate, falling near the anterior third. Dorsal
margins nearly horizontal; the anterior lateral margin broad-
ly rounded to obscurely truncate, the posterior lateral margin
more oblique than the anterior, the base line nearly hori-
zontal medially, broadly upcurved in front. Posterior area
flattened but with no defined rostrum. Lunule and escut-
cheon not developed. Entire outer surface finely threaded
with wavy radials, irregular in prominence and arrangement,
running about 6 to the millimeter toward the ventral margin
"'Mansfield, W. C., Fla. State Geol. Survey Bull. 8, p. 149, 1932.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 41

and double that number in the umbonal area. Ligament ex-
ternal, the groove deep and the nymph relatively wide. Denti-
tion delicate, a slender spur from the lunular region carried
across the cardinals. Hinge of right valve not well preserv-
ed. A laminar anterior cardinal indicated, a heavier medial
cardinal and the margin of the ligament nymph pinched and
elevated, possibly to function as a posterior cardinal. A
slender laminar anterior cardinal in the left valve, a bifid
medial cardinal, and a slender but elevated posterior cardinal.
No trace of laterals in either valve. Interior retaining the
scars rather clearly. Anterior adductor scar pyriform, the
posterior semi-elliptical, both of them placed well up under
the dorsal margins. Pallial sinus very deep; the dorsal mar-
gin nearly horizontal, its squarely truncate lateral extremity
in line with the umbos, its ventral margin running backward
at a very low angle to the obscure pallial line. Edges of
valves thin, faintly rayed but not crenate.
Dimensions of cotypes: Right valve, height, 20.5 milli-
meters; width, 31.8 millimeters; thickness, 6.0 millimeters.
Left valve, height, 20.4 millimeters; width, 31.6 millimeters;
thickness, 6.3 millimeters.
Type material: Two cotypes, a right and a left valve
not of the same individual, U. S. Nat. Mus. No. 372907.
Type locality: Shell Bluff, Shoal River, Walton County,
Florida. Shoal River formation of the Alum Bluff group.
The species is named in honor of Miss Nell L. Bowen. Her
cheerful interest and continuing patience have relieved the
drudgery associated with the Alum Bluff manuscript since
the beginning of the work.
Pleiorytis bowenae is closely related to P. centenaria Con-
rad of the Chesapeake fauna. It is not so large, it is thinner,
and, as a rule, more elongated transversely, and the spur
from the lunular region is less prominent than in the Chesa-
peake species. In all superspecific characters the two forms
are identical.
Distribution: Shoal River formation, Shell Bluff on Shoal
River, Walton County, Florida.
Semele species cf. S. chipolana Dall
Plate 7, Figures 5-7
The most of the material upon which Semele chipolana





42 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

was established is so fragmentary that it is difficult to prop-
erly evaluate the age and individual as contrasted with the
specific variations. Among the collections made by the State
Geological Survey of Florida is a young specimen (U. S.
Nat. Mus. No. 372910) from the Chipola of Ten Mile Creek
which though rather more compressed and more finely sculp-
tured than the usual S. chipolana is probably the young of
that species. It is considerably lower relatively than the type
of S. chipolana, a difference due in part to age variation and
probably in part to the greater relative height of the shells
from Alum Bluff, the type locality, than of those from
Bailey's Ferry and Ten Mile Creek. This young shell is
figured in the hope that it may be of use in determining rela-
tionships which can not be clearly established from the
available material.
Another left valve (U. S. Nat. Mus. No. 372911) of the
same group or species was collected at Oak Grove. This shell
is larger than No. 372910 but not fully mature. This is doubt-
less the same species as that to which reference was made
in the Alum Bluff report of 19281. The material is still in-
sufficient to determine the relationship between the Oak
Grove and the Chipola species. There are certain differences
in the character of the lunule and the escutcheon and the
posterior area and in the spacing of the concentric lamellae.
They may be specific but that still remains to be proven.
Donax species
Plate 8, Figure 1
A single broken right valve of a very large Donax 32 milli-
meters high and probably more than 55 millimeters wide was
recovered from the Shoal River formation on White's Creek.
There is nothing like it in the described Alum Bluff faunas.
The umbones are at the apex of an angle of about 110" and
behind them, the shell is acutely truncated much as it is in
Donax striatus Linnaeus of the recent West Indian fauna.
As in Donax striatus, also, the medial portion of the disk is
somewhat flexuous, and the subsurficial radial sculpture
strong and relatively coarse upon the disk, but finer and more
crowded upon the posterior area. In external aspect these
"Gardner, Julia, The molluscan fauna of the Alum Bluff group
of Florida: U. S. Geol. Survey Prof. Paper 142-E, p. 204, 1928.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 43

two species are very similar although the Miocene form is
a little larger than any of the Recent representatives observ-
ed. In hinge characters, however, they differ widely. The
Miocene specimen is very much worn but, certainly the an-
terior lateral which is well developed in the Recent species
was not present in the Miocene. The other hinge elements
of the Miocene valve are apparently normal for Donax sensu
strict. The ligament groove is short and deep. The car-
dinals were probably normal and there are remnants of a well
defined lateral socket. The characters of the interior are
obscure. The muscle scars seem rather small. The pallial
sinus is rudely quadrate, almost horizontally directed, the
ventral margin possibly coalescent, and the dorsal parallel to
it and about the same distance from the ventral that the ven-
tral is from the margin. The marginal creation is not very
strong though probably much of it has been lost by wearing.
This species of which we have no worthy type material,
combines in a remarkable manner the external aspect of the
Donax of the type commonly known as Chion with the hinge
characters of the much smaller, more cylindrical Paradonax,
the type of which was described from the lower and middle
Miocene of southern France.
The specimen is No. 372889 of the U. S. National Museum,
collected by the Florida Geological Survey from the Shoal
River outcrop in a gully on the east side of White's Creek,
200 feet south of the bridge on the Knox Hill road, 6.7 miles
by road south of Argyle and about 1.7 miles southeast of
Eucheeanna, Walton County, Florida. This is the same
locality as that indicated by Sta. No. 10603 of the U. S.
Geological Survey.

Mactra (Mactrotoma) profragilis Gardner, new species
Plate 8, Figures 13, 14
Shell rather small for the group, exceedingly thin and
fragile, highly polished, ovate-trigonal in outline. Posterior
area slightly depressed, sharply delimited by a difference in
the concentric wrinkling and by the raised thread along the
margin. Umbones smoothly contoured, the tips proximate
and feebly prosogyrate. Lunule elongate-cordate, defined by
a shallow depression; escutcheon narrow lanceolate. Surface





44 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

smooth excepting for an incremental wrinkling, most pro-
nounced upon the posterior area, and short, fortuitous, obli-
que threadlets in front of the rostral extremity. Traces of
color banding still preserved. Ligament marginal, the area
of attachment short and slender, the resilium strong and at-
tached to a fairly deep but not very wide chondrophore,
apically roofed, the chondrophore and ligament area separat-
ed by a shelly plate. Anterior and posterior cardinal lamellae
thin, sharp and prominent, the rather broad trigonal area
between them for the reception of the V-shaped cardinal of
the left valve; a deltoid accessory lamina developed slightly
dorsal and anterior to the anterior cardinal lamina; dorsal
and ventral clasping lamellae developed upon the walls of
the anterior and posterior lateral grooves near the umbones,
the dorsal lamellae springing from the walls at right angles,
the anterior ventral lamella in line with the anterior cardinal
and its accessory. Lateral grooves not entirely analogous
to the lateral grooves of Hemimactra since the teeth of the
opposing valve are short and contained only in the dorsal
end while the ventral half is filled only with the soft parts.
Adductor scars fairly large and rather high, the anterior
very obscure. Pallial sinus broad and deep, the anterior ex-
tremity in line with the umbones, the ventral margin near
but not confluent with the pallial line. Pallial line obscure.
Interior of shell somewhat wrinkled and rayed, especially to-
ward the ventral margin.
Dimensions of holotype, right valve: Height, 31.8 milli-
meters; width, 46.01 millimeters; thickness, 8.0 millimeters.
Type material: Ho;otype, a right valve, U. S. Nat. Mus.
No. 372908.
Type locality: Oak Grove, Yellow River, Okaloosa Coun-
ty, Florida. Oak Grove sand of Alum Bluff group.

Mactra profragilis differs from the late Tertiary and Re-
cent M. fragilis in the higher, more inflated umbones, the
more narrow chondrophore and the greater concentration of
the hinge.
Distribution: Oak Grove sand, Oak Grove, on Yellow
River, Okaloosa County, Florida. Collected by the State
Geological Survey of Florida. Rare.




ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 45

Sphenia senterfeiti Gardner, new species
Plate 8, Figures 2-4
Shell small, very thin and irregular in its transversely ellip-
tical outline, concave, probably inequivalve. Beaks broad,
flattened upon their summits, the tips acute, turned forward
and proximate, placed well in advance of the medial line.
Anterior extremity rounded with comparative regularity.
Posterior extremity flaring for the extrusion of the long
siphons. Ventral margin more or less bent inward. Outer
surface wrinkled and cross wrinkled, the irregularity of the
sculpture abruptly increasing when the shell is about half
grown and taking on the irregularities of the situs. An
acutely angular posterior keel developed upon the earlier
portion of the shell, obsolete ventrally, the sculpture behind
it a little sharper than upon the disk. Ligament internal;
right chondrophore subumbonal; left chondrophore rather
small, spreading and obliquely produced posteriorly, merging
with the dorsal margin. Hinge edentulous excepting for the
modification of the right anterior dorsal margin into a small
trigonal subumbonal denticle. Interior more or less warped
and rippled, the shell so thin that it reflects the irregularities
of the outer surface. Scars not showing up well on so thin
a lining. Anterior adductor obscure, linguiform, rather
low; posterior adductor more distinct, larger, semi-elliptical,
placed high up under the dorsal margin. Pallial sinus broad,
and broadly rounded at its extremity near the median ver-
tical. Pallial line obscure.
Dimensions of cotypes: Right valve, height, 3.3 milli-
meters; width, 6.0 millimeters. Left valve, height, 3.5 milli-
meters; width, 6.0 millimeters.
Type material: Two cotypes, a right and a left valve not
of the same individual, U. S. Nat. Mus. No. 372905.
Type locality: U. S. G. S. Sta. No. 10659, Tanner's Mill
(old Senterfeit mill), 4 miles southwest of Laurel Hill, Oka-
loosa County, Florida.
Sphenia senterfeiti is the first of the genus to be recorded
from the Alum Bluff faunas. The later Tertiary Sphenias
are all of them heavier shells, more or less attenuated pos-
teriorly.
Distribution: Oak Grove sand, locality 10659P.





46 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Corbula (Caryocorbula) cala Gardner, new species
Plate 8, Figures 8-12
Shell solid but well formed; inequivalve, the margin of the
right valve folded over the left, the overlapping more pro-
nounced posteriorly than anteriorly. Transversely trigonal
ovate in outline, sharply rostrate behind. Umbones broad,
moderately prominent, slightly anterior, the tips proximate,
incurved and prosogyrate. Anterior end of shell symmetric-
ally rounded. Posterior end produced along the rostrum and
obtusely pointed. Base line gently upcurved laterally.
Lunule and escutcheon indicated by the evanescence of the
sculpture but not sharply defined. Sculpture concentric, in-
cremental and irregular upon the umbonal area, becoming
stronger toward the ventral margin and developing into
clapboard-like ribs with a dorsal overlap; rostral sculpture
relatively fine sharp and irregular; sculpture similar in char-
acter upon the two valves, possibly a little stronger upon the
left. A very obscure radial warping of the shell barely per-
ceptible but no radial sculpture. Ligament internal, mounted
upon a cuneate chonodrophore projecting from the left pos-
terior dorsal margin and received in a deep, subumbonal
socket in the right valve. Right cardinal heavy, horizontally
compressed, upturned at the tip, received in a corresponding-
ly wide socket beneath the left umbo. A small tubercle at
the margin of the chondrophore in the left valve and a cor-
responding depression in the right valve. Mantle cavity ex-
cavated, its margin warped and thickened. Adductor scars
large and distinct, the anterior reniform and very close to
the anterior extremity, the posterior broad, rounded ventral-
ly, truncate dorsally, set close to the posterior lateral margin.
Pallial line distinct, running closer to the margin posteriorly
than anteriorly, slightly incurved between the posterior ven-
tral extremity and the adductor scar. Gutter near the margin
of the right valve indicating the line of closure of the left
and running very close to the edge anteriorly, not so close
posteriorly.
Dimensions of holotype, double valves: Height, 9.2 milli-
meters; width, 14.2 millimeters; thickness, 6.4 millimeters.
Type material: Holotype, double valves of a single indi-
vidual, U. S..Nat. Mus. No. 372900.





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 47

Type locality: Collected by the State Geological Survey of
Florida. Gully on the east side of White's Creek, 200 feet
south of the bridge on the road to Knox Hill, 6.7 miles by road
south of Argyle and about 1.7 miles southeast of Eucheeanna,
Walton County, Florida. Shoal River formation of Alum
Bluff group.
Corbula (Caryocorbula) cala is one of the group of Chipola
species represented by C. sphenia and sarda Dall and franci
Gardner. Corbula sphenia is larger and more strongly and
regularly sculptured; Corbula sarda is more flexuous and
attenuated behind and more regularly sculptured; and Cor-
bula franci is smaller and not so finely sculptured.
The type is unique.
Distribution: Shoal River formation. Collection made by
the State Geological Survey of Florida from the same locality
as that represented by No. 10603.
Architectonica quadriseriata waltonensis Gardner, new subspecies
Plate 9, Figure 1; Plate 10, Figure 4
Shell of normal size for the group and of normal propor-
tions. Whorls very broadly and feebly inflated, 7 or 8 in
number, including the small, loosely coiled protoconch of
11/2 volutions. External sculpture dominantly spiral, similar
in general character and in the details of the number and
arrangement of the spirals to A. quadriseriata s.s. but more
subdued and less persistent; incrementals more shallow and
more distant than in the Jamaican or even in the Oak Grove
race, obliquely undercutting the low fillets so that they ap-
pear to be made up of a series of minute, overlapping tiles;
sulci beginning to evanesce as early as the sixth whorl, where
they appear for the most part as incised, linear grooves cut-
ting obliquely across the spirals, replaced on the body whorl
by microscopically fine striae; basal sculpture much reduced.
Umbilical pit outlined by a wide and heavily corrugated
spiral, which is separated by a profound sulcus from the
somewhat rugose band outside of it. Periphery outlined by
a heavy cord and just within it but separated from it by a
very fine threadlet, another cord of almost equal size and
also simple. Area between the umbilical and peripheral
spirals about half the width of the entire base, feebly convex




4S FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

and smooth in the adult excepting for 2 or 3 faint spiral stria-
tions and incremental scratches which radiate from the um-
bilical keel. Sutures so deeply channeled that the profile of
the spire is interrupted and the whorls assume a gibbosity
greater than that which they really possess. Characters of
aperture normal for the species. Umbilical funnel a trifle
narrower and less open than that of A. quadriseriata s.s.
Dimensions of holotype: A slightly imperfect specimen,
height, 14.0 millimeters; maximum diameter, 26.0 millimeters.
Type material: Holotype, U. S. Nat. Mus. No. 351515.
Type locality: U. S. G. S. Sta. No. 3742, Shell Bluff, Shoal
River, Walton County, Florida.
The subspecies differs from the Bowden form only in the
somewhat less flattened whorls, the less ornate and less per-
sistent sculpture, the channeled suture, the slightly smaller
umbilicus, and in the development of only one instead of two
spiral bands encircling the heavily corrugated umbilical
spiral. The Oak Grove race is intermediate in the character
of its sculpture between the Bowden and the Shoal River
races. In the profile of the spire and the consequent outline
of the umbilicus it resembles the former. Arch itectomica bel-
lastriata var. vicksburgensis (Dall) is probably more close-
ly allied with the granulata group than it is with the bel-
lastriata. It differs from the Shoal River race in the some
what more elevated and more rounded outline, rather finer
sculpture upon the sides of the spire, and the more ornate
base and most obviously in the exposure of the peripheral
spiral as a fine piping directly behind the suture line. The
species is the most common representative of the genus with-
in the Shoal River beds.
Distribution: Shoal River formation, localities 3742a,
3856", 2238', 5618r.
Architectonica alvear Gardner, new species
Plate 9, Figure 2; Plate 10, Figures 5-6
Shell of moderate size for the genus, somewhat rounded,
suggesting in outline a very low beehive. Whorls about 71/2
in number, including the small, loosely coiled protoconch of
approximately 1V- volutions, the initial half turn, however,
largely immersed. Whorls of conch flattened between the
channeled sutures, the body whorl somewhat tumid, sharply




ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 49

angulated at the periphery, and flattened upon the base.
Sculpture very simple for the genus; earliest spiral initiated
as in others of the granulata group directly behind the
suture on the first turn of the conch, growing increasingly
prominent and more sharply granulose until the ultima, where
it tends to flatten out and become more simple; a second spiral
introduced soon after the first directly in front of the suture
but this is quickly reduced to a series of fine incremental
puckerings; wide, flattened interspiral area smooth excepting
for oblique incremental rugae which are most pronounced
upon the spire and correspond in number to the posterior
puckers and the granules of the anterior spiral. Periphery out-
lined by a very heavy, rounded, feebly corrugated cord which
appears to be wider on the basal surface than upon the apical,
and a second strongly rounded and well elevated cord de-
veloped upon the base just within the peripheral spiral and
.separated from it by only a deep linear sulcus. Umbilical
carina sharp, outlined by a wide denticulate spiral; outer
margin separated from the flattened, more or less rugose
spiral which surrounds it by a narrow but deep channel; area
between the umbilical and peripheral spirals flattened, smooth
excepting for radial growth striae and a vague spiral sulcus a
little less than half-way from the periphery to the umbilicus.
Umbilical pit rather large, open to the apex, the wall display-
ing the umbilical keel of the successive whorls. Shell broken
at the mouth and characters of aperture not well known.
Dimensions of imperfect holotype: Height, 17.0 milli-
meters; maximum diameter, 25.0 millimeters.
Type material: Holotype, U. S. Nat. Mus. No. 350446.
Type locality: U. S. G. S. Sta. 5633, Oak Grove, Yellow
River, Okaloosa County, Florida. Oak Grove sand of Alum
Bluff group.

Architectonica alvear is allied to A. amphiterma Dall from
the Miocene of Maryland. It is relatively higher, however,
with a more prominent and, on the spire, more sharply an-
nulate anterior spiral. The young are discoidal in outline.
Architectonica quadriseriata waltonensis is lower than A.
alvear and the whorls are more flattened and more deeply
channeled at the sutures. Intermediate spiral fillets are pres-





50 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

ent in iwaltonensis which on the later whorls are as strong
as the anterior and posterior spirals.
The species is restricted in its distribution to the Oak Grove
sand.
Distribution: Oak Grove sand, localities 2646c, 5632r, 5633r,
7054.
Architectoni-a (Psilaxis) verecunda Gardner, new species
Plate 10, Figures 1-3
Shell small, a much depressed cone, acutely angulated at
the periphery, flattened upon the basal surface, and broadly
rounded in the apical region. Nucleus porcellaneous, large,
ill-shaped, broadly inflated, completing a little more than a
single revolution, strongly differentiated from the conch both
by the abrupt change in the texture of the shell and by the
initiation of the conchal sculpture. Whorls of conch 3 in
number in the unique type, which is probably not fully ma-
ture; earliest whorl obscurely rounded, the two later volu-
tions flattened laterally. Sculpture very simple; two narrow
ornate bands of equal width marked off by incised lines, the
one placed directly in front of the suture and the other direct-
ly behind it; a second anterior, non-crenate, and slightly
narrower band delimited by a more feebly incised line, set
about one-third the distance from the anterior to the posterior
suture. Suture line deeply impressed but very narrow.
Periphery of body wound with a very strong cord with a
second cord equally strong revolving on the base directly in
front of it and separated from it by only a linear interspace.
Area between the umbilicus and periphery broadly rounded,
devoid of spiral sculpture excepting for a feeble thread, de-
limited by incised lines revolving about one-third the distance
from the periphery to the umbilical keel and marking the
outer limit of the radial sulci of the umbilical area; keel
sharply crenulated, set off by a deeply impressed channel.
Incremental sculpture manifested in the puckerings of the
base, the crenate bands upon the spire, and the very faint
striae on the smooth medial portion of the whorl. Aperture
rudely quadrate, sharply angulated at the peripheral and
umbilical keels and at the union of the parietal wall with the
labrum and the pillar. Outer lip very thin and sharp. Body
wall thinly glazed. Umbilicus small, its diameter less than




ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 51

one-third that of the entire base, persistent to the apex, re-
vealing within, the umbilical keels of the earlier volutions.
Dimensions of holotype: Height, 4.0 millimeters; maxi-
mum diameter, 6.5 millimeters.
Holotype: U. S. Nat. Mus. No. 352117.
Type locality: U. S. G. S. Sta. 5618, 31/2 miles southwest
of De Funiak Springs, Walton County, Florida.
Architectonica verecunda is interesting as the first record
in the Floridian Miocene of the section Psilaxis Woodring
(Miocene mollusks from Bowden, Jamaica: Carnegie Inst.
Washington Pub. No. 385, p. 355, from the Bowden of the
West Indies. Type, Architectonica krebsii March. Recent
in the West Indies and Florida). The section is characterized
by the very large nuclear whorl and a sculpture of spiral
cords girdling the periphery and the umbilicus. All of the
observed species are small. Recent representatives have
been recorded from the western Atlantic and the western
Pacific. The Shoal River shell differs from the two described
Bowden species in slight details of the spiral sculpture and
in the stronger incremental striae which have sufficient depth
and regularity to bead the spirals upon the dorsal surface.
Distribution: Shoal River formation, locality 5618r.
Melanella (Melanella) makista Gardner, new species
Plate 10, Figures 7-9
Shell imperforate, straight, moderately slender and rather
large for the group. Porcellaneous, highly polished, devoid
of sculpture. Whorls narrow, appressed, slowly and regular-
ly increasing in diameter, flattened laterally, slightly under-
cut anteriorly, probably exceeding 20 in number in the perfect
adult. Body whorl about one-third as high as the entire
shell, broadly rounded at the periphery. Extreme tip not
preserved and characters of protoconch not known. Faint
brownish flammules which may be the remnants of a colour
pattern occasionally visible on the conch. Suture strong.
Aperture obliquely lobate, acutely angulated posteriorly.
Outer lip expanded and slightly pouting, not thickened,
rounding smoothly into the labium which is thickened and
closely appressed against the body wall. Umbilicus entirely
closed but faintly indicated by a very narrow, depressed and





52 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

arcuate area along the margin of the sharply raised and
thickened basal portion of the inner lip.
Dimensions of holotype: Height, 23.0+ millimeters;
greatest diameter, 6.4 millimeters; height of aperture, 5.0
millimeters.
Type material: Holotype and 1 juvenile paratype, U. S.
Nat. Mus. No. 483782. A figured individual probably refer-
able to the same species.
Type locality: U. S. G. S. Sta. No. 3856, 6 miles west-
northwest of Mossyhead, Shoal River, Walton County, Flor-
ida. Shoal River formation of the Alum Bluff group.
Melanella makista resembles Melanella magnoliana Gard-
ner and Aldrich from the higher Miocene of Florida and the
Carolinas in the many slowly enlarging whorls separated by
conspicuous suture lines. The Alum Bluff species is the more
slender, and the body whorl relatively shorter and more
abruptly constricted.
Distribution: Shoal River formation, locality 3856".
Typhis pterinus Gardner, new species
Plate 10, Figure 10
Shell polished, of moderate dimensions for the genus, rather
thin and quite slender excepting for the flange-like varices;
spire scalariform; body including the varices cuneate; maxi-
mum diameter falling a little in front of the median hori-
zontal. Whorls of conch probably 6 in number in the adult,
very closely appressed, the posterior margin creeping up a
little upon the preceding whorl, acutely angulated at the
periphery. Shoulder slightly concave, more or less corrugat-
ed by the intervarical tubes; sides of whorls flattened, slightly
inclined toward the axis; body somewhat rounded medially,
gently concave anteriorly. Sutures linear, inconspicuous,
zigzaging around the varices. Protoconch known only from
the final whorl but apparently small, smooth, and very highly
polished. Opening of conch indicated by a change in the tex-
ture of the shell and by the initiation of the axial sculpture
in the form of obtuse tubercles. Primary varices 4 in num-
ber, the terminal varix a rather broad, laminar flange, the
other 3 body varices compressed, acutely angulated ridges,
terminating at the shoulder in compressed, posteriorly direct-




ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 53

ed tubes;- short circular tubes also developed in the inter-
varical areas directed at right angles to the axis of the shell,
perforate at their outer extremities but only the last tube in
direct communication with the body cavity. Spiral sculpture
restricted to very fine, feeble, rather distant, and more or less
irregular lirations, often obsolete altogether upon the spire,
strengthening toward the aperture and usually 3 to 5 in
number upon the terminal wing, absent upon the anterior
canal. Incrementals macroscopic, retractive and somewhat
arcuate upon the shoulder, flexuous upon the anterior canal
and relatively prominent upon the apertural surface of the
terminal varix, where they are quite strongly crenulated and
are puckered into the fine, sharp spiral lirae. Apertural
opening rather small, oval in outline, widening a little pos-
teriorly, the margin elevated slightly above the body surface;
peristome continuous, smoothly rounded; inner surface very
smoothly glazed; area between the labral varix and that di-
rectly behind it filled with a rather thin, trigonal plate. An-
terior canal short, compressed, feebly inclined toward 11h,
right, the former canals, one to each varix, superimposed but
diverging very slightly at their anterior extremities.
Dimensions of holotype: Height, 20.0+ millimeters; maxi-
mum diameter including varices, 13.0 millimeters; diameter
at right angles to maximum diameter, 8.0 millimeters.
Type material: Holotype, U. S. Nat. Mus. 371860.
Type locality: U. S. G. S. Sta. No. 3742, Shell Bluff, Slihal
River, Walton county Florida. Shoal River formation of
Alum Bluff group.
Typhis pterinus is certainly very closely allied to Typhis
alatus subsp. obesus Gabb, but the spire is more elevated in
proportion to the body, and the spiral sculpture is sharper
and more regular than in either the Bowden or the Chipola
individuals referred to obesus or in Typhis harrisi Olsson
and the subspecies waltoneusis Mansfield. The slender spire
and the sharper spirals suggest alatus s.s., but if Sowerby's
figure is correct the aperture in the Santo Dominican species
is less ovate than in that from Shoal River.
Distribution: Shoal River formation, localities 3742p,
3856", 5184r.




54 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Alectrion waltonensis Gardner, new species.
Plate 9, Figures 3, 4
Shell of moderate dimensions, ovate-conic in outline.
Whorls of spire trapezoidal, very narrowly tabulated poster-
iorly, the later whorls increasing a little more rapidly in
diameter than the earlier; volutions between 91/ and 10 in
all, 3 of this number being included in the smooth, naticoid
protoconch. Initial turn minute, flattened posteriorly, al-
most entirely submerged in the succeeding whorl; remaining
whorls broadly convex, flattening somewhat toward the close
of the protoconch, increasing regularly and rather rapidly
in height. Dividing line between conch and protoconch in-
dicated by a slight change in the texture of the shell and by
the abrupt initiation of the axial sculpture. Conchal sculp-
ture cancellate, the spirals appearing later than the axials
and dominated by them. Axials very narrow, sharply pinch-
ed, vertical or nearly so, 10 to 20 in number upon the first
whorl of the conch, increasing to 23 upon the body of the type,
persisting from suture to suture and well down to the base
of the body, subnodose posteriorly upon the later whorls;
intercostal areas, concave, a little wider than the costals.
Presutural spiral initiated near the beginning of the second
turn of the conch; other spirals not developed until the third
or fourth whorl, appearing on the later whorls of the spire
as low, broad, flattened bands separated from one another
by linear sulci, the posterior of the three a little more prom-
inent than the two in front of it and a little wider than that
directly in front of the suture, from which it is separated
by a channel of approximately its own width; presutural
spiral strongly nodulated at the intersection with the axials;
spirals upon the body of the type 9 in all, including the rather
heavily nodulated posterior spiral, the less strongly nodose
spiral in front of it, 4 equal and regularly spaced fillets upon
the medial portion of the whorl, and 3 narrower, more distant
and quite sharply nodulated basal spirals; posterior margin
of basal sulcus defined by a narrow, corrugated thread. Basal
sulcus narrow but sharply concave. Fasciole coarsely but
not strongly lirate. Suture lines deeply impressed, crenulat-
ed by the costate of the preceding whorl. Aperture obliquely
lenticular, acutely angulated and sulcated posteriorly. Outer




ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 55

lip thickened a little behind the margin, sharp-edged, denticu-
late within, the denticles elongated normal to the margin,
alternating in size posteriorly, most prominent medially, per-
sistent to the mouth of the canal. Inner margin of aperture
strongly concave, the labium thickened, reverted, and spread
in a broad arc over the parietal wall and pillar; denticles ir-
regularly developed, that directly in front of the posterior
commissure and the three or four upon the pillar heavier
than the intermediate denticles; edge of pillar elevated into
a sharp fold terminating at the mouth of the aperture in a
rather prominent denticle. Anterior canal very short and
sharply recurved. Fasciole rather wide, cuneate, its flexuous
extremity forming one arm of the broad, obliquely U-shaped
terminal notch, the base and outer arm of the U being formed
by the raised posterior margin of the basal sulcus.
Dimensions of holotype: Height, 12.7 millimeters; maxi-
mum diameter, 7.5 millimeters.
Type material: Holotype and juvenile paratype, U. S.
Nat. Mus. No. 371811.
Type locality: U. S. G. S. Sta. No. 3742, Shell Bluff, on
Shoal River, Walton County, Florida. Shoal River forma-
tion of the Alum Bluff group.
Alectrion waltonensis, like most of the members of the
genus, offers a wide range of variation in the details of the
sculpture, especially of the spirals. The outline varies at
the type locality from rather squat, ovate-conic to elevated-
conic. It runs through much the same range of variation
as A. harrisi Maury, the analogous form in the Chipola
fauna, though the latter runs about a third smaller and is
frequently more slender than any specimens of waltonensis.
Alectrion dalli Maury from the Oak Grove fauna is also
smaller and more coarsely and rudely sculptured. A. berthae
Maury is taller relatively, and the posterior tabulation of
the whorls is more pronounced. The number of the whorls
both in the conch and protoconch of the four species in ques-
tion is very close, although it runs a little higher in the conch
of waltonensis and a little lower in the conch and protoconch
of harrisi. The axials of waltonensis range from 18 to 25
upon the body and upon the first whorl of the conch there
may be as many as 20. The axials are constantly narrower




5ti FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

and sharper, however, than in any of the analogous forms
and, as a rule, more strongly nodose posteriorly. The axials
upon the later whorls of the spire are less numerous than
in berthae Maury but more numerous than in either dalli
or harrisi. The spiral sculpture and the resulting cancella-
tion is much more marked in waltonensis at least upon the
body. There is not a very wide range in the number of spirals
in waltonensis, though the variation is quite marked in their
relative width and in the degree of elevation. In some in-
dividuals the interspirals are linear and not very deeply im-
pressed; in others they are almost or quite as wide as the
spirals and very squarely and deeply channeled. The second
spiral in front of the posterior suture may be almost as
prominent and almost as strongly nodose as the presutural
spiral, or it may be similar in character to those in front of it.
The subspecies deleta has been isolated because of the late
and feeble development of the spiral sculpture, the subdued
axials, and the relatively slender, scalariform outline.
Alectrion waltone sis is more abundant at the single hori-
zon at which it occurs than any of its congeners or analogues
;a other horizons in the Alum Bluff group.
Distribution: Shoal River formation, localities 3742",
:856r, 5184', 3731r, 3732r, 3733r, 5195r, 5080', 3748P, 2238,
56'18P.

Alectrion waltonensis deleta Gardner, new subspecies
Plate 9, Figure 5
Shell of moderate dimensions, ovate-conic in outline, acute-
ly tapering; aperture less than half as long as the entire
shell. Whorls of conch 6 in number, trapezoidal, narrowly
tabulated posteriorly, the body whorl broadly rounded at
the base and abruptly constricted into the well defined basal
sulcus. Suture lines inconspicuous, finely crenulated by the
costals of the preceding whorl. Protoconch small, smooth,
probably polished in fresh specimens, three-whorled; initial
turn minute, immersed at the tip; succeeding volutions broad-
ly rounded, increasing regularly both in diameter and alti-
tude. Dividing line between conch and protoconch indicated
by a slight change in the texture of the shell and by the abrupt
appearance of the axial sculpture. Axials narrow, acutely





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 57

rounded, abruptly elevated, approximately vertical, dissect-
ed by the posterior sulcus so that the extremities of the ribs
form a circlet of obtuse tubercles in front of the suture;
axials 10 to 15 in number on the earliest whorls, increasing
to 23 upon the body, uniform in elevation from the sulcus to
the anterior suture and well down to the base of the body,
subequal and equispaced, separated by broadly concave inter-
costals, slightly wider than the costals. Spiral sculpture
incised rather than elevated, feeble excepting for the poster-
ior sulcus which partially dissects tle ribs; 3 low spiral fillets
developed in the type between the posterior sulcus and the
anterior suture; grooves equal and equispaced, restricted
entirely to the intercostal areas, least feeble upon the body.
Base of body girded with 4 low fillets which become increas-
ingly narrow and decreasingly low anteriorly. Basal sulcus
threaded with a single sharp lira. Anterior fasciole ir-
regularly lirate, margined posteriorly with a sharply elevated
ridge. Aperture narrow, obliquely lenticular, acutely angu-
lated and sulcated posteriorly, narrowly constricted anterior-
ly. Outer lip flaring in front, abruptly contracted at the
mouth of the canal, broadly varicose behind the thin, sharp
margin; inner surface of labrum threaded with 6 or 7 lirae,
the posterior corresponding in position to the posterior sul-
cus, the anterior indicating the entrance to the canal; medial
lira the shortest and the most elevated, those behind it less
pliominent and more distant than those in front. Inner
margin of aperture strongly concave, heavily reinforced, the
wash spread in a broad, sharply defined arc from the poster-
ior commissure to the anterior canal; a series of irregular,
elongated denticles developed just within the margin, the
posterior the most prominent and placed directly across from
the posterior liration on the inner margin of the labrum; edge
of pillar acute and proximate to the anterior liration on the
inner margin of the labrum. Anterior canal short, recurved;
terminal notch narrow and very oblique, its inner arm formed
by the sinuous lateral margin of the anterior fasciole, its
outer by the produced keel which outlines the posterior mar-
gin of the fasciole.
Dimensions of holotype: Height, 11.4 millimeters; length
of aperture, 5.8 millimeters; maximum diameter, 6.5 milli-
meters.




58 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

Type material: Holotype, U. S. Nat. Mus. No. 371812.
Type locality: U. S. G. S. Sta. No. 5079, one-half mile be-
low Shell Bluff, Shoal River, Walton County, Florida. Shoal
River formation of the Alum Bluff group.
The subspecies is apparently a local variation of A. wal-
tonensis s.s., from which it differs in the somewhat more
slender and scalariform outline and in the more subdued
sculpture, both axial and spiral. The axials run the same in
number but are not so sharply pinched as a rule as in wal-
tonensis s.s. The spiral sculpture on the early whorls is
restricted to the posterior sulcus, and even on the later whorls
is very feeble excepting for the basal spirals and seemingly
impressed rather than elevated. Aside from the age varia-
tions, the subspecies is quite constant at the single locality
at which it is represented, although the number of incised
lines between the posterior sulcus and the base of the whorl
may be increased to 4 or even 5.
Distribution: Shoal River formation, locality 5079".
Alectrion dystakta Gardner, new species
Plate 9, Figures 6-8
Shell rather small, thin, elongate-conic in outline. Basal
sulcus ill-defined. Aperture in mature individuals less than
half as high as the entire shell. Whorls of spire trapezoidal
or feebly convex, the body broadly rounded. Number of
whorls running up to 8 in the largest individuals, more fre-
quently 7 or 61/2. Protoconch of moderate dimensions,
smooth, polished, naticoid, performing 31/2 volutions; initial
turn minute, somewhat inflated but almost entirely immersed
in the succeeding whorl; remaining nuclear turns increasing
in height and diameter with a moderate degree of rapidity.
Line of demarcation between the conch and protoconch rather
obscure, indicated by the gradual introduction of the axial
sculpture. Axials very narrow both at the summit and the
base, obtuse, feebly arcuate, uniform in prominence between
the sutures, more or less obsolete upon the base of the body,
varying widely in number,-from 15 to 25 or 26 upon the
penultima, irregular in size and spacing upon the body; in-
teraxial areas shallow, frequently wider than the axials.
Spiral sculpture feeble and irregular; grooves usually 6 or
7 in number upon the penultima, the posterior sulcus deeply





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 59

incised and in some individuals dissecting the ribs, the medial
spirals very feeble but becoming increasingly less so toward
the anterior suture; anterior spiral groove often almost as
deeply impressed as the posterior. Base of the body sculp-
tured with low, flattened bands 8 or 9 in number, as a rule,
which become increasingly narrower and more sharply ele-
vated anteriorly. Fasciole threaded with about half a dozen
lirae equal in size and linearly spaced. Suture line distinct,
finely crenulated by the costae of the preceding evolution.
Aperture obliquely lenticular in outline, obtusely angulated
posteriorly. Outer lip almost vertical medially, often feebly
emarginate at the base, possibly for the extension of the eye-
stalks, thin-edged but broadly varicated externally a little
behind the margin, thickened and rather finely lirate internal-
ly. Inner wall of aperture quite strongly concave, washed
with rather a heavy glaze, the margin of which extends in
a broad arc from the commissure to the base of the pillar;
an amorphous denticle or two sometimes developed upon the
pillar and more rarely upon the parietal wall; edge of pillar
acute, slightly elevated. Anterior canal incipient. Terminal
notch very broad, not very deep, somewhat obliquely directed.
Dimensions of holotype: Height, 7.5 millimeters; length
of aperture, 3.5 millimeters; maximum diameter, 3.8 milli-
meters. Paratype (an immature individual): Height, 5.3
millimeters; length of aperture, 2.7 millimeters; maximum
diameter, 3.0 millimeters.
Type material: Holotype and 2 paratypes, U. S. Nat. Mus.
No. 371815.
Type locality: U. S. G. S. Sta. No. 5618, 31/2 miles south-
west of De Funiak Springs, Walton County, Florida. Shoal
River formation of Alum Bluff group.
A. dystakta is rather closely related to A. waltonensis.
The latter, however, is much larger and decidedly stouter
than dystakta; the conch performs, as a rule, 2 or 21/ more
volutions, the axials are more or less A-shaped instead of
being obtuse upon their summits, and are very narrow at the
base, the spirals are fewer and more uniform, and the den-
ticulation both upon the outer and inner wall of the aperture
is much more developed.





60 FLORIDA GEOLOGICAL SURVEY-BULLETIN FOURTEEN

A. dystakta offers a bewilderingly wide range of variation
in relative proportions, the number of axials, and in the char-
acter and relative prominence of the spirals. The small thin
shell and the numerous, arcuate, more or less irregular axials
are usually sufficient to isolate the species. The spirals are
also numerous, usually 6 at least upon the penultima, and,
as a rule, they appear as unequally impressed, sublinear sulci.
They may, however, be approximately equal and the spiral
sculpture as a whole may appear to be elevated rather than
depressed. The terminal varix is conspicuously broad, and
there are not uncommonly remnants of former varices to
be seen upon the shell.
Alectrion dystakta is apparently restricted in its distribu-
tion to the environs of the type locality.
Distribution: Shoal River formation, localities 5618e,
7261r, 7264P.
Alectrion grapta Gardner, new species
Plate 9, Figure 9
Shell rather small, slender, elongate-conic in outline.
Whorls probably 5 in number in an adult conch but only a
little more than 4 in the type. Protoconch not very large,
obtuse, smooth, and highly polished; initial turn minute,
broadly inflated, almost entirely submerged in the succeeding
whorl; remaining 21/ volutions increasing in height and
diameter with a moderate degree of rapidity. Dividing line
between the conch and protoconch rather obscure, indicated
by the gradual initiation of the axial sculpture; spiral sculp-
ture not developed until the last half of the first post-nuclear
turn. Axials very narrow, acute, persisting from suture to
suture and well down to the base of the body, approximately
uniform in prominence throughout their extent though tend-
ing to be slightly nodose posteriorly; from 14 to 16 in number
upon the later whorls of the spire and half as many again
upon the earlier. Spiral sculpture, taking the form of more
or less deeply incised linear grooves, very feeble upon the
earliest turns; posterior sulcus broader and deeper than
those in front of it, outlining a presutural fillet which is, in
some individuals, strong enough to feebly nodulate the costals
which it overrides; sulci between the posterior groove and
the anterior suture 4 in number in the type, frequently 5,





ADDITIONS TO MOLLUSCAN FAUNA ALUM BLUFF GROUP 61

equal and equispaced, obsolete upon the summits of the cost-
als; anterior and medial portion of the body sculptured like
the later whorls of the spire; base of the body channeled with
5 increasingly wider and deeper grooves, the intervening
areas becoming increasingly narrower and more elevated
anteriorly; basal sulcus ill-defined. Fasciole coarsely thread-
ed with 4 irregular lirae. Sutures distinct, impressed, crenu-
lated in harmony with the costals of the preceding turn.
Aperture rather narrow, obliquely lenticular, acutely angu-
lated at the posterior commissure, broadest in front of the
median horizontal. Labrum asymmetrically arcuate, abrupt-
ly constricted at the base, thickened externally a little behind
the margin, reinforced within by rather prominent lirae (5
in number in the type), most prominent just before they
abruptly evanesce a short distance within the margin. Inner
wall of aperture smoothly but quite strongly concave; a
heavy wash of callus spread in a broad, sharply defined arc
from the posterior commissure to the anterior extremity of
the pillar; a single rather prominent tooth developed upon
the parietal wall directly in front of the commissure; other
less elevated denticles usually present upon the pillar wash
of the adult and on the anterior portion of the body wall;
edge of pillar acutely elevated; anterior canal moderate,
broad, very short, and sharply recurved; terminal notch
broad, moderately deep, obliquely directed.
Dimensions of holotype: Height, 6.0 millimeters; length
of aperture, 2.5 millimeters; maximum diameter, 2.6 milli-
meters.
Type material: Holotype, U. S. Nat. Mus. No. 371829.
Type locality: U. S. G. S. Sta. No. 3742, Shell Bluff, Shoal
River, Walton County, Florida. Shoal River formation of
the Alum Bluff group.
Alectrion grapta is characterized by the rather slender,
elevated spire and the incised spiral sculpture.
Distribution: Shoal River formation, localities 3742'1,
3748r, 5618P.

















PLATES 1 -10








PLATE 1


Figures 1-2. Anadara (strebla subsp.?) metastrebla Gardner,
new species. (p. 9).
1. Exterior of holotype (left valve) : Height, 22.3 milli-
meters; width, 35.6 millimeters.
2. Interior of holotype.
Figures 3-4. Anadara gunteri Gardner, new species (p. 11).
3. Exterior of cotype (right valve) : Height, 29.5 milli-
meters; width, 37.3 millimeters.
4. Exterior of cotype (left valve) : Height, 26.0 milli-
meters; width, 30.0 millimeters.
Figures 5-6. Crenella armstrongi Gardner, new species (p. 13).
5. Exterior of holotype, left valve: Height, 4.0 milli-
meters; width, 3.0 millimeters.
6. Interior of paratype, right valve: Height, 2.3 milli-
meters; width, 1.8 millimeters.
Figures 7-9. Chlamys (Nodipecten) pyx Gardner new species
(p. 19).
7. Exterior of paratype (juvenile left valve) : Height,
26.5 millimeters; width, 25.5 millimeters.
8. Exterior of cotype (left valve) : Height, 46.4 milli-
meters; width, 47.0 millimeters.
9. Exterior of cotype (right valve) : Height, 53.5 milli-
meters; width, 56.1 millimeters.








GEOLOGICAL DEPARTMENT


6 7


BULLETIN FOURTEEN, PLATE 1






GEOLOGICAL DEPARTMENT


BULLETIN FOURTEEN, PLATE 2














PLATE 2


Figure 1. Chlamys (Lyropecten) nematopleura Gardner, new
species (p. 14).
Interior of holotype (right valve) : Height, 100.0
millimeters; width, 95.0- millimeters.
Figures 2-3. Chlamys (Lyropecten?) nicholsi neotera Gardner, new
subspecies? (p. 16).
2. Exterior of cotype (right valve) : Height, 59.0 milli-
meters; width, 56.5 millimeters.
3. Exterior of cotype (left valve) : Height, 59.0 milli-
meters; width, 55.3 millimeters.










PLATE 3


Figure 1. Crassatellites (Scambula) densus Dall (p. 22).
Exterior of right valve: Height, 33.5 millimeters,
width, 53.5 millimeters.
Figure 2. Chlamys (Lyropecten) nematopleura Gardner, new
species (p. 14).
Exterior of holotype (right valve): Height, 100.0+
millimeters; width, 95.0+- millimeters.








BULLETIN FOURTEEN, PLATE 3


[68]


GEOLOGICAL D~ IEPARTMENT'I





BULLETIN FOURTEEN, PLATE 4


[69]


GEOL~OGICAL DEPARTMENT








PLATE 4


Figure 1. Astarte (Ashtarotha) species (p. 20).
Exterior of right valve: Height, 14.6 millimeters;
width, 16.2 millimeters.
Figures 2-5. Crassatellites (Scaambula) densus Dall (p. 22).
2. Exterior of left valve: Height, 26.0 millimeters; width,
37.5 millimeters.
3. Exterior of left valve: Height, 29.5 millimeters; width,
42.0 millimeters.
4. Exterior of right valve: Height, 28.0 millimeters;
width, 42.5 millimeters.
5. Exterior of right valve: Height, 30.0 millimeters;
width, 49.0 millimeters.
Figures 6-9. Phacoides (Callucina) cala Gardner, new species
(p. 27).
6. Exterior of cotype (right valve): Height, 10.7 milli-
meters; width, 11.0 millimeters.
7. Interior of cotype (right valve).
8. Interior of cotype (left valve) : Height, 10.2 milli-
meters; width, 10.7 millimeters.
9. Exterior of cotype (left valve).


[70]






PLATE 5


Figure 1. Venericardia (Pleuromeris) aposcitula Gardner, new
species (p. 24).
Exterior of cotype (right valve) : Height, 3.0 milli-
meters; width, 3.0 millimeters.
Figures 2-3. Phacoides (Parvilucina) diktyota Gardner, new
species (p. 26).
2. Exterior of holotype (right valve): Height, 4.0
millimeters; width, 4.0 millimeters.
3. Interior of holotype.
Figure 4. Venericardia (Pleuromeris) aposcitula Gardner, new
species (p. 24).
Exterior of cotype (left valve) : Height, 3.1 milli-
meters; width, 3.3 millimeters.
Figures 5-7. Diplodonta (Phlyctiderma) (glos subsp. ?) lampra
Gardner, new species (p. 28).
5. Exterior of cotype (left valve): Height, 8.4 milli-
meters; width, 8.6 millimeters.
6. Interior of cotype (left valve).
7. Interior of cotype (right valve): Height, 8.4 milli-
meters; width, 8.5 millimeters.
Figures 8-9. Transennella caryera Gardner, new species (p. 29).
8. Exterior of holotype (right valve): Height, 4.6
millimeters; width, 5.2 millimeters.
9. Interior of holotype.
Figures 10-13. Pitar (Hysteroconcha [Lamelliconcha]) cypta Gard-
ner, new species (p. 31).
10. Interior of holotype (left valve) : Height, 12.3 milli-
meters; width, 13.2 millimeters.
11. Exterior of holotype.
12. Hinge of immature paratype (left valve): Height,
5.5 millimeters; width, 6.3 millimeters.
13. Interior of immature paratype (right valve) : Height,
7.7 millimeters; width, 8.0 millimeters.
Figures 14-15. Chione (Lirophora) cymaina Gardner, new species
(p. 36).
14. Exterior of cotype (right valve) : Ieight, 32.3 milli-
meters; width, 39.1 millimeters.
15. Exterior of cotype (left valve) : Height, 33.0 milli-
meters; width, 35.0 millimeters.
Figures 16-17. Venericardia (Megacardita) hesperide Gardner,
new species (p. 23).
16. Exterior of holotype (right valve): Height, 47.0
millimeters; width, 53.0+ millimeters.
17. Interior of holotype.
[711







BULLETIN FOURTEEN, PLATE 5


10


15


13


14


Ix, 2.


16


[72]


G-EOLOGICAL DEPARTMENT1~I,1'










BULLETIN FOURTEEN, PLATE 6


4




































[73]
S. ....


















:., . < ^





[73]


OkXEOLOGICAL DEPARTMENT







PLATE 6


Figures 1-2. Petricola? senterfeiti Gardner, new species (p. 38).
1. Exterior of holotype (left valve): Height, 13.0 milli-
meters; width, 17.5 millimeters.
2. Interior of holotype (left valve).
Figures 3-4. Pleiorytis centenaria Conrad (p. 39).
3. Interior of right valve from U. S. G. S. Sta. 10535,
near the James River about half way between In-
dian Point and Coggins Point, Prince George County,
Virginia; Yorktown formation: Height, 50.0 milli-
meters; width, 70.0 millimeters.
4. Interior of left valve from U. S. G. S. Sta. 10204,
Tormentor Creek, 2 miles north of Smithfield,
Isle of Wight County, Virginia; Yorktown forma-
tion: Height, 41.0 millimeters; width, 62.0 milli-
meters.
Figure 5. Pleiorytis bowenae Gardner, new species (p. 40).
Exterior of cotype (right valve) : Height, 20.5 milli-
meters; width, 31.8 millimeters.
Figures 6-7. Asaphis deflorata (Linnaeus) ; genotype of Asaphis
Modeer, U. S. Nat. Mus. No. 73118, from Abaco,
the Bahama Islands (p. 39).
6. Interior of right valve; Height, 36.0 millimeters;
width, 60.0 millimeters.
7. Interior of left valve of the same individual.
Figures 8-9. Pleiorytis bowenae Gardner, new species (p. 40).
8. Interior of cotype (right valve) ; Height, 20.5 milli-
meters; width, 31.8 millimeters.
9. Interior of cotype (left valve) : Height, 20.4 milli-
meters; width, 31.6 millimeters.


[74]







PLATE 7


Figures 1-2. Chione (Chione) oulotricha Gardner, new species
(p. 33).
1. Exterior of holotype (right valve): Height, 28.4
millimeters; width, 36.2 millimeters.
2. Interior of holotype.
Figures 3-4. Callocardia (Agriopoma) calceola Gardner, new species
(p. 30).
3. Exterior of holotype (left valve) : Height, 41.0 milli-
meters; width, 54.0 millimeters.
4. Interior of holotype.
Figures 5-7. Semele species cf. S. chipolana Dall (p. 41).
5. Exterior of left valve, U. S. Nat. Mus. No. 372911:
Height, 22.5 millimeters; width, 30.0 millimeters.
6. Exterior of left valve, U. S. Nat. Mus. No. 372910;
Height, 12.0 millimeters; width, 16.8 millimeters.
7. Interior of U. S. Nat. Mus. No. 372910.
Figure 8. Chione (Lirophora) crossota Gardner, new species
(p. 34).
Exterior of holotype (right valve) : Height, 25.0 milli-
meters; width, 33.8 millimeters.


[75]







BULLETIN FOURTEEN, PLATE 7


7


[76]


GEOLOGICAL DEPARTMENT








BULLETIN FOURTEEN, PLATE 8


6


13


11


[77]


GE~OLOGICAL DEPARIZTMENT


~^~p~:
.I
X3







PLATE 8


Figure 1. Donax species (p. 42).
Exterior of right -alve, U. S. Nat. Mus. No. 372889:
Height, 32.0+- millimeters; width, 55.0 milli-
meters.
Figures 2-4. Sphenia senterfeiti Gardner, new species (p. 45).
2. Exterior of cotype (left valve) : Height, 3.5 milli-
meters; width, 6.0 millimeters.
3. Interior of cotype (left valve).
4. Interor of cotype (right valve) : Height, 3.3 milli-
meters; width, 6.0 millimeters.
Figures 5-7. Lithophaga cookei Gardner, new species (p. 14).
5. Lateral profile of holotype (mold of double valves):
Height, 8.8 millimeters; width, 23.2 millimeters.
6. Holotype viewed from the front.
7. Profile of paratype (individual encased in a calcare-
ous covering) : Length of imperfect tube, 26 milli-
meters.
Figures 8-12. Corbula (Caryocorbula) cala Gardner, new species
(p. 46).
8. Dorsal view of holotype (double valves of a single
individual) : Height, 9.2 millimeters; width, 14.2
millimeters; thickness, 6.4 millimeters.
9. Interior of right valve of holotype.
10. Exterior of right valve of holotype.
11. Interior of left valve of holotype.
12. Exterior of left valve of holotype.
Figures 13-14. Mactra (Mactrotoma) .profragilis Gardner, new
species (p. 43).
13. Interior of holotype (right valve) : Height, 31.8
millimeters; width, 46.0+ millimeters.
14. Exterior of holotype.






PLATE 9


Figure 1. Architectonica quadriseriata waltonensis Gardner, new
subspecies (p. 47).
Basal view of holotype: Height, 14.0 millimeters;
maximum diameter, 26.0 millimeters.
Figure 2. Architectonica alvear Gardner, new species (p. 48).
Basal view of holotype: Height, 17.0 millimeters;
maximum diameter, 25.0 millimeters.
Figures 3-4. Alectrion waltonensis Gardner, new species (p. 54).
3. Apertural view of holotype: Height, 12.7 millimeters;
maximum diameter, 7.5 millimeters.
4. Tip of juvenile paratype, xl0.
Figure 5. Alectrion waltonensis delta Gardner, new subspecies
(p. 56).
Apertual view of holotype: Height, 11.4 millimeters;
maximum diameter, 6.5 millimeters.
Figures 6-8. Alectrion dystakta Gardner, new species (p. 58).
6. Tip of juvenile paratype, xl0.
7. Apertural view of holotype: Height, 7.5 millimeters:
maximum diameter, 3.8 millimeters.
8. Apertural view of adolescent paratype: Height, 5.3
millimeters; maximum diameter, 2.7 millimeters.
Figure 9. Alectrion grapta Gardner, new species (p. 60).
Apertural view of holotype: Height, 6.0 millimeters;
maximum diameter, 2.6 millimeters.






BULLETIN FOURTEEN, PLATE 9


6 x1o
6


[80]


C'rlj.'jOLOGICL DEPARTMiENT'l








BULLETIN FOURTEEN, PLATE 10


4




x44
















X3






Ow.


















10 6
[81]


GEOLOGICAL DEPARTMENTYT






PLATE 10


Figures 1-3. Architectonica (Psilaxis) verecunda Gardner, new
species (p. 50).
1. Apical view of holotype: Height, 4.0 millimeters;
maximum diameter, 6.5 millimeters.
2. Apertural view of holotype.
3. Basal view of holotype.
Figure 4. Architectonica quadriscriata waltonensis Gardner, new
subspecies (p. 47).
Apertural view of holotype: Height, 14.0 millimeters;
maximum diameter, 26.0 millimeters.
Figures 5-6. Architectonica alvear Gardner, new species (p. 48).
5. Apertural view of holotype: Height, 16.0 millimeters;
maximum diameter, 25.0 millimeters.
6. Apical view of holotype.
Figures 7-9. Melanella (Melanella) makista Gardner, new species
(p. 51).
7. Apertural view of juvenile paratype: Height, 7.8
millimeters; maximum diameter, 2.7 millimeters.
8. Apertural view of holotype: Height, 23.0 millimeters;
maximum diameter, 6.4 millimeters.
9. Specimen figured to show an unusually well rounded
body whorl: Height, 20.0+ millimeters; maximum
diameter, 6.0 millimeters.
Figure 10. Typhis pterinus Gardner, new species (p. 52).
Apertural view of holotype: Height, 20.0- milli-
meters; maximum diameter including varices, 13.0
millimeters.