Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN" MAEINE MOLLTJSKS. 71
The type and another specimen, Cat. No. 249719, U.S.N.M., come
from Port Alfred (Coll. No. 991). The type has nine postnuclear
whorls remaining, the nucleus, and probably the first two of the
succeeding turns, having been lost. It measures: Length, 11 mm.;
diameter, 4.3 mm.
Another specimen from the same locality is entered' as Cat. No.
186861, U.S.N.M. (Coll. No. 231).
Family PYRAMIDELLIDAE.
Genus PYRAMIDELLA Lamarck.
PYRAMIDELLA (ORINELLA) AFRICANA, new species.
Plate 14, figs. 2, 4.
Shell elongate-conic, light brown. Nuclear whorls two, small,
planorboid, having their axis at right angles to that of the succeeding
turns, in the first of which they are very slightly immersed. Postnuclear
whorls almost flat, feebly shouldered at the summit, marked
by very fine incremental hues, and exceedingly fine spiral striatums.
Suture moderately constricted. Periphery of the last whorl well
rounded. Base short, well rounded, narrowly umbilicated, marked
like the spire. Aperture subquadrate; posterior angle acute; outer
lip thin; inner Up almost vertical, strongly reflected, provided with a
fold a little anterior to its insertion.
Cat. No. 186841a, U.S.N.M. contains three specimens from Port
Alfred (Coll. No. 208). Two of these are young individuals having
the nucleus, and one an adult shell, which has lost the nuclear whorls,
and probably the first four succeeding turns. The adult specimen,
the type, has seven whorls remaining, and measures: Length, 6.1
mm.; diameter, 1.8 mm. One of the young specimens has eight
postnuclear whorls, and measures : Length, 3 . 7 mm. ; diameter, 1 .2 mm.
PYRAMIDELLA (ORINELLA) ALFREDENSIS, new species.
Plate 14, figs. 5, 7.
Shell elongate-conic, milk white. Nuclear whorls very small, one
and three-fourths, planorboid, having their axis at right angles to
that of succeeding turns. The left side of the nucleus projects considerably
beyond the outline of the postnuclear spire. Postnuclear
whorls almost flat; feebly shouldered at the summit, marked by ex-
ceedingly fine, retractive, incremental lines, and numerous microscopic
spiral striations. Suture moderately constricted. Periphery
of the last whorl well rounded. Base well rounded, decidedly um-
bilicated, marked like the spire. Aperture subquadrate; posterior
angle acute; outer lip thin; inner Up very oblique, and decidedly
reflected, provided with a strong fold near its insertion; parietal wall
glazed with a thin callus.