Bulletin - United States National Museum - Smithsonian Institution

192 BULLETIN 91, UNITED STATES NATIONAL MUSEUM.
little wider than the spaces that separate them. Interior showing
the external sculpture through the substance of the shell. Entire
inner basal margin marked by alternating squarish teeth and
depressions, forming a series of sockets and teeth which alternate in
the opposing valves. The character of the hinge is shown in our
detailed figure.
The type and another valve, Cat. No. 251049, U.S.N.M., come
from Port Alfred (Coll. No. 1566). The type measures: Altitude, 1.2
mm.; length, 1.2 mm.
Family CARDITIDAE.
Genus CARDITA Bruguiere.
CARDITA VARIEGATA TURGIDA Krauss.
Cat. No. 32055, U.S.N.M., one specimen from the Cape of Good
Hope. Cat. No. 43172, U.S.N.M., two valves from the Cape of
Good Hope.
CARDITA (CARDITAMERA) LATICOSTATA Smith.
Cat. No. 186929, U.S.N.M., four valves from Port Alfred (Coll.
No. 299). Cat. No. 251010, two valves from the same locality (Coll.
No. 1527).
Genus VENERICARDIA Lamarck.
VENERICARDIA ELATA Sowerby.
Cat. No. 186931, U.S.N.M., two specimens from Port Alfred (Coll.
No. 301).
VENERICARDIA AFRICANA, new species.
Plate 48, fig. 3; plate 54, figs. 5, 6.
Shell small, rather thick, rose colored. Umbones bent decidedly
forward, forming a rather strong-pointed hook. Surface marked by
12 strong, rounded, radiating ribs, of which the central ones are the
heaviest. These ribs give the ventral edge a somewhat fluted appearance.
In addition to these radiating ribs, the shell is marked
with strong, concentric, sublamellar threads, which pass equally strong
over the ribs and the intercostal spaces. The character of the hinge
is shown in our detailed sketch.
Cat. No. 187171, U.S.N.M., contains the type, which comes from
Port Alfred (Coll. No. 720). It measures: Altitude, 3.1 mm.; length,
2.8 mm.
Cat. No. 251012, U.S.N.M., contains two additional valves from the
same locality (Coll. No. 1529).
Genus THECALIA H. and A. Adams.
THECALIA CONCAMERATA Bruguiere.
Cat. No. 137, U.S.N.M., 12 specimens collected by William Stimpson
on the North Pacific exploring expedition at the Cape of Good Hope.