Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN MARINE MOLLUSKS. 75
The type and another specimen, Cat. No. 249709, U.S.N.M., come
from Port Alfred (Coll. No. 981). The type has six postnuclear
whorls, and measures: Length, 4 mm.; diameter, 1.2 mm
Genus TURBONILLA Risso.
TURBONILLA tPTYCHEULIMELLA) ERNA, new species.
Plate 16, fig. 2.
Shell very small, elongate-conic, bluish white, translucent. Nuclear
whorls at least two, well rounded, forming a depressed helicoid spire,
the axis of which is almost at right angles to the axis of the succeeding
turns. The nuclear spire is about one-fourth immersed in the first
of the succeeding whorls. Postnuclear whorls slightly rounded,
strongly appressed at the summit, marked by extremely feeble,
almost vertical axial ribs which are so poorly defined that they can
scarcely be counted. In addition to the axial sculpture, the entire
surface of the whorls is marked by closely spaced, microscopic, spiral
striations. Sutures well constricted. Periphery of the last whorl
somewhat angulated. Base short, well rounded. Aperture elongate-
ovate; posterior angle obtuse, outer lip thin, imier lip strongly
curved and slightly reflected; parietal wall covered by a thin callus.
The type and another specimen, Cat. No. 250371, U.S.N.M., come
from Port Alfred (Coll. No. 1244). The type has seven postnuclear
whorls, and measures: Length, 3 mm.; diameter, 0.7 mm.
TURBONILLA (CHEMNITZIA) GEMMULA Smith.
Cat. No. 186847, U.S.N.M., contains two specimens of this species
from Port Alfred (Coll. No. 214).
TURBONILLA (CHEMNITZIA) KRAUSSI Clessin.
Cat. No. 186843a, U.S.N.M., one specimen from Port Alfred (Coll.
No. 210a).
TURBONILLA (PSELLIOGYRA) ADABA, new species.
Plate 15, fig. 5.
Shell broadly elongate-conic, white. Nuclear whorls well rounded,
smooth, obliquely immersed in the first of the succeeding turns, above
which the tilted edge of the last volution only projects. Postnuclear
whorls almost flattened, very strongly, tabulatedly shouldered at the
summit, crossed by strong, very regular, somewhat sinuous, slightly
protractive, axial ribs, of which 20 occur upon the second and third,
22 upon the fourth and fifth, 24 upon the sixth, and 28 upon the
penultimate turn. These ribs extend prominently from the shoulder,
which they render crenulated, to the periphery of the turn. Inter-
costal spaces a little wider than the rib. A spiral cord in the
intercostal is present about one-fifth of the space between the sutures