Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN MARINE MOLLUSKS. 107
second at some little distance posterior to the suture. Beginning
with the thud whorl, a slender, spiral thread makes its appearance
half way between the two strong cords ; this increases steadily in size
and on the last turn it bears nodules almost as strong as those of the
other two cords. In addition to the spiral sculpture, the whorls are
marked by slender, vertical, axial ribs, the junction of which with
the spiral cords render them tuberculated. Of these ribs, 20 occur
upon all but the last, which turn has 22. The spaces inclosed
between the axial ribs and the spiral cords form well impressed pits.
The tubercles of the cord. at the summit are strongly rounded; those
of the median cord are merely thickened lines at the junction on the
first two whorls where they occur, while on the last, they are oval,
their long axis coinciding with the spiral cord. Those of the third
cord are truncated posteriorly, sloping gently anteriorly. Sutures a
little broader than the sulci between the spiral cords. Periphery of
the last whorl marked by a spiral sulcus which is about as broad as
the one separating the supraperipheral from the median cord on the
last whorl. Base well rounded, marked by two spiral cords, the first
of which is immediately below the periphery, the second half way
between this and the insertion of the columella. In addition to the
above mentioned sculpture, the entire surface of the shell is marked
by fine lines of growth and microscopic, spiral striations. Aperture
strongly channeled anteriorly, feebly so posteriorly, decidedly
patulous at the junction of the outer and basal lip; outer lip thin,
showing the external sculpture within and rendered sinuous at the
edge by this sculpture; columella short, very stout, covered on its
inner edge by a strong callus which is reflected over the parietal
wall and renders the peritreme complete.
Cat. No. 249680, U.S.N.M., contains three specimens from Port
Alfred (Coll. No. 952). One of these, the type, has six postnuclear
whorls, and measures: Length, 3 mm.; diameter, 1.4 mm.
TRIPHORIS, species?
Cat. No. 250353, U.S.N.M., contains the tip of a dusky cylindric
species, which we are unable to identify, from Port Alfred (Coll.
No. 1226).
TRIPHORIS FUSCESCENS Smith.
The United States National Museum contains four lots of this
species from Port Alfred, as follows: Cat. No. 186808, two specimens
(Coll. No. 174). Cat. No. 220061, one specimen (Coll. No. 173a).
Cat. No. 227721, two specimens (Coll. No. 816). Cat. No. 249674,
two specimens (Coll. No. 946).
TRIPHORIS CEREA Smith.
Cat. No. 249681, U.S.N.M., contains three specimens from Port
Alfred (Coll. No. 953).