Academy of Natural Sciences

List of Land and Freshwater Mollusks Collected on Andros, Bahamas

Author(s): Henry A. Pilsbry
Source: Proceedings of the Academy of Natural Sciences of Philadelphia, Vol. 82 (1930), pp.
297-302
Published by: Academy of Natural Sciences
Stable URL: https://www.jstor.org/stable/4064078
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 LIST OF LAND AND FRESHWATER MOLLUSKS COLLECTED
ON ANDROS, BAHAMAS

BY HENRY A. PILSBRY.

The mollusks catalogued below were collected by Mr. Maurice Black with
the aid of grants from the Percy Sladen Memorial Fund and the Rouse-Ball
Fund, except those reported from Williams Island and Billy Island, which
were taken by Doctor E. E. L. Dixon of the International Expedition to
the Bahamas. The cerions collected have been listed in the preceding
paper. Several species either new or previously not reported from Andros
will be found among those enumerated here. The chief interest of the
material lies in the fact that there was a wiaely spread fresh water or very
slightly brackish water fauna, represented by species of Physa, Amnicota,
Hydrobia, Potlymesoda and apparently Anomalocardita. This occurred
throughout the region examined, both superficially and in holes sunk about
to sea-level.
The description of a marine gastropod, Volvula (Tectibranchiata), is
appended.
A series of these species has been deposited in the museum of the Acad-
emy; another is to go to the Linnean Society of London.

Cepolls (Hemitrochus) varians (Mke.)

Money Cay, fossil; north side of Wide Opening, living and fossil; north
shore Lake Forsyth; Stafford Creek. Also Lyford Cay, N. P.

Cepolis (Hemitrochus) xnaynardi (Pils.)

Fossil on Money Cay; north side Wide Opening, living and fossil; north
shore Lake Forsyth; Stafford Creek. Fossil on Great Stirrup Cay.

Cepolis (Plagioptycha) duclosiana (For.)

Fossil on Money Cay; north side Wide Opening; Stafford Creek.

Polygyra plana bahamensis Van.

Billy Island, fossil; Wide Opening, living and fossil; Forsyth Lake, west
end and north shore; Stafford Creek; fossil on Money Cay.

Hojeda inaguensis (Weini.)

Williams Island, off the western point of Andros.

Opeas pumilum (Pfr.)

West end of Lake Forsyth.

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298 PROCEEDINGS OF THE ACADEMY OF [VOL. LXXXII

Leptinaria striosa abdita (Poey).

Western end of Lake Forsyth. The specimens are rather small, but be-
long, I do not doubt to this species of Cuba and Jamaica. Two measure:
Length 4.5 mm., diam. 1.8 mm., length of aperture 1.5 mm.; 63 who
Length 5 mm., diam. 1.85 mm., length of aperture 1.8 mm.; 6i whorls.
Laevoleacina solidula (Pfr.)

North side Wide Opening, living and fossil; Lake Forsyth; Stafford
Creek.

Melaniella gracillima bahamensis (Bartsch).

West end of Lake Forsyth.

Hawaiia minuscula (Binn.)

West end of Lake Forsyth.

Gastrocopta pellucida (Pfr.)

Purser Point; Stafford Creek Camp.

Pedipes tridens (Pfr.)

Billy Island.

Plecotrema cubensis (Pfr.)

Billy Island.

Melampus gundlachi (Pfr.)

Stafford Creek; Billy Cay, fossil.

Detracia bulloides (Mtg.)

Stafford Creek.

Physa cubensis (Pfr.)

Lake Forsyth, and fossil at various depths down to 8 feet in the marl;
Stafford Creek.
Only small specimens were found, up to nearly 6 mm. long, of 41 whorls,
all apparently immature. This is doubtless the species which has been
reported from the Bahamas as Physa acuta Drap.

Opisthosiphon bahamensis (Shuttl.)

Fossil on Money Cay; Purser Point; Wide Opening, living and fossil;
north shore of Lake Forsyth; Billy Island, fossil; Stafford Creek.
Opisthosiphon androsense new species. Plate 30, fig. 9.

Andros: Stafford Lake, in gravel on shore. Type No. 151789 ANSP.,

collected by Maurice Black.
Shell resembles O. bahamense, but it is smaller with coarser sculpture,
the axial laminae being widely spaced, about 4 in 1 mm. on the face of the
last and penult whorls, the spiral cords more distinct than in 0. bahamense.
The aperture is slightly longer than wide, formed as in 0. bahamnense.
Length 8.7 mm., diam. 5 mm., length of aperture, inside 2.5 mm.; 32
whorls remaining.

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1930] NATURAL SCIENCES OF PHILADELPHIA 299

Chondropoina soror new species. Plate 30, fig. 6.

New Providence: Nassau. Type and four other specimens No. 44483
ANSP., collected by C. J. Maynard.
The shell resembles the Cuban C. obesum Mke. rather closely, but differs
by having the umbilicus reduced to a minute perforation. The shell is
conic, narrowly truncate, four strongly convex whorls remaining. Color
pinkish cinnamon, becoming a little darker on the first whorl. The surface
is lusterless, with sculpture of spiral cords, about 6 on the ante-penult
whorl, more numerous by the intercalation of threads on the last whorl;
crossed by axial threads narrower and closer than the spiral cords, the
upper ends crenulating the suture. The aperture is ovate, the peristome
expanded, flat, a little dilated posteriorly, and with a narrow ledge built out
around the opening.
Length 11.2 mm., diam. 6.8 mm., length of aperture with peristome 5
mm. Type.
Length 12.3 mm., diam 7.8 mm., length of aperture with peristome 5.5
mm.
Length 8 mm., diam. 4.8 mm.
While it seems unlikely that a shell of this size would remain undiscov-
ered in the neighborhood of Nassau, I am unable to find an Antillean species
with which it agrees, but it is so similar to C. parvicaymanense of Little
Cayman that it seems possible that Maynard got his labels or shells mixed,
and that this is really from some of the Cayman group. It differs from
C. parvicaymenense by the more compact form, the sutures being less im-
pressed, and by the noticeably coarser sculpture. It was received from
Mr. Maynard in 1897. It is certainly not C. obesum Mke., which I have
collected at Matanzas Bay, and which differs constantly by the conspicuous
umbilicus. C. carenasense P. & H. has a larger umbilicus and more numer-
ous spiral cords.

Syncera concolor (C. B. Ad.).

Stafford Lake; Turner Sound and Cabbage Creek in the Wide Opening
region; fossil at Billy Island.

Schasicheila bahamensis (Pfr.)

North shore and west end of Lake Forsyth; fossil at Money Cay.

Alcadia blacki new species. Plate 22, figs. 1, 2, 3.

Andros: Money Cay, Middle Bight, fossil in lime rock. Type No.
151790 ANSP. and paratypes collected by Maurice Black.
The shell is somewhat smaller than A. minima Orb., with more strongly
convex whorls and deeper suture. The surface appears to be nearly smooth.
The aperture is not so wide as in A. minima. The outer lip has a blunt,
rounded edge. The columella is concave in front, projecting in a blunt
point at the base, with a shallow bay in the basal lip before its union with
the columella. This bay is much shallower, less obvious than in A. minima,
its right side without a definite limiting angle. The umbilical callus is

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300 PROCEEDINGS OF THE ACADEMY OF [VOL. LXXXII

thick and bordered by a furrow for some distance back of the baso-columel-
lar point.
Height 2.7 mm., diam. 4 mm.; 34 whorls.
This cannot be the species which Mr. W. Bendall recorded1 as Alcadia
minima Orb. from New Providence, as he states that his form is three times
the size of Cuban ones he had seen.

Amuicola forsythi new species. Plate 22, fig. 7.

Andros: shore of Lake Forsyth. Type 151792 ANSP., collected by

Maurice Black.
The shell is rather widely umbilicate, ovate-conic, the general outlines of
the spire straight. The apex is rather acute. Whorls 51, strongly convex,
joined by a deeply impressed suture, the last whorl regularly and strongly
convex. Surface smooth, lines of growth faintly visible. The aperture is
broadly oval, higher than wide, very slightly oblique. Peristome is blunt,
continuous, the columellar margin slightly dilated, the parietal margin very
shortly free.
Length 4.3 mm., diam. 2.7 mm., length of aperture 1.75 mm. (Fig. 7.)
No living examples were taken, but they are probably to be found in
places where there is aquatic vegetation. Many of the shells have an
ochraceous-tawAly stain, but none appear to retain the original color.
In holes sunk around Lake Forsyth to a depth of about 8 feet, at Turner
Sound, west of Lake Forsyth, and in bottom samples taken in Stafford Lake,
about 17 miles northeast, a much smaller form was taken in some abundance.
One from Turner Sound measures: length 2.1 mm., diam. 1.3 mm., length
aperture 1 mm.; 5 whorls. There are some larger examples, 3.5 to 4 mm.
long, however, as in the hole sunk at Station 36, which make transitions to
the typical form. The parietal callus is partly adnate in most examples of
these small forms, and the umbilicus is often less widely open.
Potacmopyrgus coronatus (Pfr.) and its smooth form Paludina crystal-
lina Pfr., 1840, which were called Paludestrina candeana and P. auberiana
respectively by d'Orbigny, 1846, are often found on sea beaches, washed
out of streams. The smooth phase (crystallina, auberiana) resembles the
species described above, but has a narrower umbilical perforation and less
strongly convex whorls. Potamopyrgus jamaicensis (C. B. Ad.) is also
more narrowly perforate.

Amnicola oscitans new species. Plate 22, fig. 8.

Andros: shore of Lake Forsyth. Type No. 151793 ANSP., collected

by Maurice Black.
The shell is openly umbilicate, globosely conic with short spire and
rather acute apex. The whorls are very strongly convex, joined by a deeply
impressed suture. Surface smooth. The large aperture is broadly ovate,
1 Proc. Malac. Soc. London I, p. 294.

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1930] NATURAL SCIENCES OF PHILADELPHIA 301

angular above, longer than wide. Peristome thin, adnate to the whorl for
a short distance.
Length 1.9 mm., diam 1.5 mm., length of aperture 1.1 mm. Type.
"g 1.9 "c " 1.4 " " " " 1 "
This is a very short shell with large aperture, not like any of the Antil-
lean amnicolids I have seen. Small examples were found fossil in the pits
sunk around Lake Forsyth.

Xydrobia blacki new species. Plate 22, figs. 4, 5, 6.

Andros: shore of Lake Forsyth, station 27, surface. Type No. 151791
ANSP., collected by Maurice Black.
The shell is perforate, high conic, the outlines of the spire straight, the
apex rather acute. There are 7 whorls, the first two strongly convex, the
rest weakly convex with moderately impressed suture, the last whorl
strongly convex in the peripheral region, weakly so or somewhat flattened
above it. The nearly smooth surface is faintly marked with lines of growth.
The aperture is about one-third the length of the shell, ovate, angular above,
the outer half of the peristome more curved than the columellar. The
peristome is continuous but adnate to the whorl for a short distance.
Length 6 mm., diam. 2.7 mm., length of aperture 2.1 mm. Type. -Fig. 5.
Length 4.4 mm., diam. 2.1 mm., length of aperture 1.6 mm.; 6 whorls.
Fig. 6.
Length 4.6 mm., diam. 1.9 mm., length of aperture 1.4 mm.; 7 whorls.
Fig. 4.

A peculiar, turrited form with weakly convex whorls, the last one
strongly convex peripherally. It is unlike any West Indian species known
to me.
This species occurred also in pits sunk around Lake Forsyth, (lots 35,
36, 37, 38), in company with Amnicola forsythi; most fossil specimens be-
ing smaller than the type.

Volvula ischnatracta new species. Text-fig. 1.

Andros Bank, west of Middle Bight, about 12 miles within the western
edge of the bank, in 31 fathoms. Type No. 151794 ANSP., collected by
the International Expedition to the Bahamas.
The shell is cylindric, tapering shortly at both ends, grayish white, thin.
The summit is rounded, without a posterior spine. The median part of the
shell has outlines only very slightly convex. Sculpture of weak growth
wrinkles, with several weakly impressed spiral lines in the posterior fourth
near the summit, and about fifteen in the anterior half of the shell. The
aperture is very narrow in the upper two-thirds, dilated in the anterior
third. The thin outer lip arches forward, being most prominent at the
lower third, then recedes, the base being somewhat effuse. The columella is
thickened and weakly convex above.
Length 2.8 mm., diam. 1 mm.
This form is chiefly notable for its very narrow contour, and the absence
of an apical spine.

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Anomalocardia nesiotica new species. Text-fig. 2.

Andros: Lake Forsyth, abundant. Type and 4 valves No. 152251

ANSP., collected by Maurice Black. Found also in the marl of Williams
Island and Turner Sound.

Fig. 1. Volvula ischnatracta. Fig. 2. Anomalacardia nesiotica. The lines represent

1 millimeter.

The shell is about like A. cuneimeris (Conrad) in shape, and resembles

that also in the teeth and the weak crenulation of the inner margin. It is
thin, ochraceous-tawny, becoming buff towards the margins; interior purple
or white. Sculpture of rather strong concentric ridges at the anterior end,
elsewhere fine irregular concentric ripples and delicate radiating lines. It
is quite unlike A. leptalea Dall of the Watlings Island lagoon.
Length 7 mm., height 5 mm., semidiam. 1.8 mm.
In some specimens the posterior part is more drawn out: length 7 mm.,
height 4.5 mm. Often the crenulation of the ventral border is very weak.
There are also numerous valves resembling A. nesiotica but without the
anterior concentric ridges. I have not satisfied myself about their identity.

Polymesoda (Pseudocyrena) colorata (Prime).

Lake Forsyth; Turner Sound.

Small valves are abundant in the marl with the preceding species and
the Amnicolidae.
EXPLANATION OF PLATE 22
Figs. 1, 2, 3.-A icadia blacki, n. sp. Type.
Figs. 4, 5, 6.-Hydrobia blacki, n. sp. Type (fig. 5) and paratypes.
Fig. 7.-A mnicola forsythi, n. sp. Type.
Fig. 8.-Amnicola oscitans, ni. sp. Type.
Fig. 9 a-d.-Cerion latisinus, n. sp. Type (Fig. a) and paratypes.
Fig. 10.-Cerion rhyssum Dall. Money Cay.
Figures 1 to 8 variously enlarged as indicated by size-marks, the rest natural size.

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PROC. ACAD. NAT. SCI. PHILA. 1930 PLATE 22

(~~~~~~~~~~~~~

1 & 3~~1

I I~~~NDOS BHIA
PILSRY.LAN A
''0~ ~ADR

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