Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN MARINE MOLLUSKS. 17
marked by 10-12 prominent, broad, low, rounded, somewhat pro-
tractive axial ribs which are truncated posteriorly by the channel, their
terminations forming cusps. Intercostal spaces about twice as wide
as the ribs. The ribbed portions of the whorls on the spire are
covered by five, equal and equally spaced, incised, spiral lines. Summit
of the whorls appressed, rendering the sutures ill defined. Base
of the last whorl moderately long, marked by the feeble continua-
tions of the axial ribs and on the posterior half by five incised spiral
lines equaling those on the spire in strength and spacing and forming
a continuous series with them. Anterior portion of base with about
seven ill-defined spiral lirations. Aperture narrowly elongate pyriform,
sinus shallow immediately below the sutures; outer lip somewhat
sinuous; columella strong, slightly sigmoid. The coloration
of the type consists of a creamy white ground, which is almost unmarked
in the subsutural channel and on the anterior half of the base
on the last turn. A few dots of brownish orange appear near the
summit between the ribs of the preceding whorls. The ribbed por-
tion of the whorl between the anterior and posterior portion of the
base is strongly mottled with brownish orange in the intercostal
spaces, less so on the summits of the ribs, while a little posterior to
the middle the base is marked by two slender spiral lines of the
same color.
The type, Cat. No. 18796, U.S.N.M., has lost the early whorls; the
four and one-half remaining measure : Length, 1 3 mm. ; diameter, 7 mm.
It comes from Port Elizabeth.
CLIONELLA SEMICOSTATA Kiener
Cat. No. 16913, U.S.N. M., one specimen from Cape of Good Hope.
CLIONELLA TURTONI, new species.
Plate 2, fig. 2.
Shell fusiform, covered with thick brownish olive epidermis.
(Nuclear whorls decollated.) Post-nuclear whorls flattened except-
ing the contraction of the anal sulcus, which is a little anterior to the
posterior third of the space between the sutures; slightly shouldered
at the summit. Subsutural cord well rounded, marked by feeble
extensions of the ribs, which have a retractive slant. Anal sulcus a
mere constriction. Posterior to the sinus the last whorl is marked by
very low, poorly developed, somewhat sinuous protractive axial ribs,
each of which bears a weak nodule at the sulcus. In addition to the
axial ribs the entire surface of the spire and base is marked by numer-
ous strong lines of growth and spiral striations, the combination of the
two giving the surface a finely reticulated appearance. Sutures
strongly marked. Periphery of the last whorl well rounded. Base
moderately long with a slender fasciole at the insertion of the col-