Bulletin - United States National Museum - Smithsonian Institution

SOUTH AFRICAN MARINE MOLLUSKS. 43
Family MITRIDAE.
Genus MITRA Martyn.
MITRA BATHYRAPHE Sowerby.
Two, Cat. No. 186736, U.S.N.M., from Port Alfred (Coll. No. 95).
MITRA CANALICULATA Sowerby. "
Cat. No. 186734, U.S.N.M., three, from Port Alfred (Coll. No. 93).
Cat. No. 272158, U.S.N.M., two from Kowie, South Africa.
MITRA CAPENSIS Dunker.
Cat. No. 186733, U.S.N.M., five, from Port Alfred (Coll. No. 92).
Cat. No. 272159, U.S.N.M., two from Kowie, South Africa.
MITRA HELENA, new species.
Shell small, wax-yellow, with two bands of white, the first of which
occupies a little more than the anterior half between the sutures,
while the second one, which is about half as wide, occupies the mid-
dle of the base. Nuclear whorls decollated. Postnuclear whorls
shouldered at the summit, marked by very strong, slightly retractive,
axial ribs, of which 16 occur upon the first of the remaining turns, 20
on the second, and 16 upon the rest. In addition to the axial ribs,
the whorls are crossed by strong spiral cords, of which five occur
between the sutures of the first three and seven upon the fourth and
last. The spaces inclosed between the axial ribs and spiral cords are
deep pits on the posterior half and deep slits on the anterior half
between the sutures. Base rendered decidedly sigmoid on the left
side by the twisting of the anterior portion; marked by the continuations
of the axial ribs which extend to the tip of the columella, and
10 spiral cords, of which the 6 posterior to the columella are like
those on the spire, while the first 2 on the columella are broader and
stronger and more rounded, the last two on the anterior end weaker.
Suture well impressed. Aperture narrow, channeled anteriorly;
posterior angle acute; outer lip marked by 12, slender, spiral lira-
tions within; columella provided with four oblique folds, which de-
crease regularly in size from the posterior to the anterior; they also
become more oblique in the same order.
The type and another specimen, Cat. No. 272156, U.S.N.M., come
from South Africa. The type has 6 whorls remaining and measures:
Length, 15 mm.; diameter, 6.6 mm. These specimens came to the
United States National Museum, labelled " Mitra daedala, Reeve,'' in
a donation by Mr. John B. Henderson, in a collection purchased from
Sowerby and Fulton. Mitra daedala of Reeve is a Philippine species,
which we have from the islands ; it is much larger than the present
species.