Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN MARINE MOLLUSKS. 197
less abruptly; the anterior dorsal margin slightly rounded, the pos-
terior less so and longer than the anterior; the ventral well rounded.
The outer surface marked by numerous, rather strong, concentric lines
of growth. The hinge is shown in our detailed figure.
Cat. No. 161, U.S.N.M., contains Gould's type of this species,
which was collected by William Stimpson on the North Pacific Exploring
Expedition at Simons Bay, Cape of Good Hope. The type
is a worn specimen, and measures: Altitude, 3.7 mm. ; length, 4.8 mm.
ERYCINA SUBRADIATA Carpenter.
Plate 46, figs. 5, 6; plate 49, fig. 2.
Shell small, of almost oval outline, with the umbones almost cen-
tral. The outer surface marked by very strong, irregularly-spaced,
lines of growth, between which very fine striations are present, and
numerous, fine, incised, radiating lines, which are strongest anteriorly
and posteriorly. The hinge is shown in our detailed figure.
The type, Cat. No. 147, U.S.N.M., was collected by William Stimpson,
on the North Pacific Exploring Expedition at Simons Bay, Cape
of Good Hope. It measures: Altitude, 3 mm.; length, 3.6 mm.
ERYCINA ALFREDENSIS, new species.
Plate 43, figs. 7, 8; plate 50, figs. 1, 2.
Shell ovate, with the umbones decidedly posterior to the middle.
Outer surface marked by fine lines of growth and numerous exceed-
ingly minute tubercles, which lend the surface a shagreened effect.
The character of the hinge is shown in our detailed sketch.
The type and another specimen, Cat. No. 187191, U.S.N.M., come
from Port Alfred (Coll. No. 742). The type measures: Altitude, 3.9
mm. ; length, 4.9 mm.
ERYCINA IMA, new species.
Plate 42, figs. 7, 8; plate 50, figs. 3, 4.
Shell small, oval. Outer surface polished, covered with an exceed-
ingly thin periostracum which lends the shell an iridescent appear-
ance. The umbones are slightly posterior to the middle. Outer sur-
face marked by fine lines of growth only. The character of the
hinge is shown in our detailed sketch.
The type and three other specimens, Cat. No. 187192, U.S.N.M.,
come from Port Alfred (Coll. No. 743). The type measures: Altitude,
1.7 mm.; length, 2.2 mm.
ERYCINA CARIFA, new species.
Plate 45, fig. 6; plate 50, figs. 5, 6.
Shell small, subcircular, slightly broader posteriorly than anteri-
orly, with the umbones almost median. Outer surface covered by a
very thin periostracum which lends the shell an iridescent appear-
80737°—Bull. 91—15 14