Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN MARINE MOLLUSKS. 203
Genus TIVELA Link.
TIVELA COMPRESSA Sowerby.
Cat. No. 19835, U.S.N.M., one specimen collected by William
Stimpson on the North Pacific Exploring Expedition at Simons Bay.
Cat. No. 186938, U.S.N.M., three valves from Port Alfred (Coll. No.
308).
TIVELA ALUCINANS Sowerby.
Cat. No. 43179, U.S.N.M., one specimen from the Cape of Good
Hope.
Genus SUNETTA Link.
SUNETTA OVALIS Sowerby.
Cat. No. 186940, U.S.N.M., seven valves from Port Alfred (Coll.
No. 310).
Genus CIRCE Schumacher.
CIRCE ALFREDENSIS, new species.
Plate 46, figs. 3, 4.
Shell oval, white or pale brown flecked with rust brown. Umbones
about one-third of the length of the shell posterior to the anterior
margin. Surface marked by strong radiating ribs which increase
in strength from the umbones toward the ventral margin. On the
posterior and anterior margins they become divaricate. There are
30 of these ribs on the valve. The spaces separating these radiating
ribs are a little less in width than the ribs, and are marked with con-
centric riblets. These riblets extend up on the sides of the ribs but
do not seem to cross their summits. The character of the hinge
is shown in our detailed sketch.
The type and another valve, Cat. No. 189441, U.S.N.M., come from
Port Alfred (Coll. No. 311). The type measures: Altitude, 11.5 mm.;
length, 16 mm.
Genus CHIONE Muhlfeld.
CHIONE, species?
Cat. No. 187180, U.S.N.M., two valves, young specimens of a
species of this genus, too poor to be specifically determined, from Port
Alfred (Coll. No. 731).
Genus ANOMALOCARDIA Schumacher.
ANOMALOCARDIA ALFREDENSIS, new species.
Plate 44, figs. 3, 4.
Shell inflated, heavy, irregularly triangular, flesh colored marked
with radiating, zigzag lines of rust brown. Outer surface polished,
marked by concentric lines of growth and somewhat crinkly, radiating
striations. The character of the hinge is shown in our detailed
sketch.