Bulletin - United States National Museum - Smithsonian Institution

78 BULLETIN 91, UNITED STATES NATIONAL MUSEUM.
The type and another specimen, Cat. No. 227732, U.S.N .M., come
from Port Alfred (Coll. No. 827). The type nas seven postnuclear
whorls, and measures: Length, 3.9 mm.; diameter, 1.1 mm.
TURBONILLA (PYRGISCUS) ATOSSA, new species.
Plate 15, fig. 1.
Shell elongate-conic, bluish-white. Nuclear whorls more than two,
smooth, the early portion obliquely immersed in the later. Post-
nuclear whorls strongly shouldered at the summit, marked by wellrounded,
somewhat retractive, strong, axial ribs, of which 16 occur
upon the first, 18 upon the second to fourth, and 20 upon the penultimate
turn. These ribs extend strongly from the summit of the
whorls to the umbilical chink. Intercostal spaces about twice as
broad as the ribs, crossed by fine, incised, spiral fines, of which 7 occur
between the shoulder at the summit and the suture on the first and
second, 9 upon the third, 15 upon the fourth and the penultimate
turn. The spaces separating these spiral striations are about twice
as wide as the striations. Sutures strongly constricted. Periphery
of the last whorl somewhat inflated, well rounded. Base moderately
long, well rounded, narrowly umbilicated, marked by the strong
continuations of the axial ribs and fine spiral striations, which become
a little closer spaced on the anterior portion than at the periphery.
Aperture pear-shaped; posterior angle obtuse; outer lip somewhat
sinuous, thick within, sloping to a thin edge; columella slender, curved,
reflected, provided with an oblique fold at its insertion; parietal wall
covered with a thick callus which gives the peristome a complete
aspect.
The type, Cat, No. 249700, U.S.N.M., comes from Port Alfred (Coll.
No. 972). It has six postnuclear whorls and measures: Length, 4.4
mm.; diameter, 1.7 mm. Cat. No. 249695, U.S.N.M., contains a
young specimen from the same locality (Coll. No. 967).
TURBONILLA (PYRGISCUS), species?
Cat. No. 186851, U.S.N.M., contains a specimen from Port Alfred
(Coll. No. 218), which has very strong protractive axial ribs, numer-
ous, finely incised, spiral striations in the intercostal spaces, and a
very pronounced plait on the pillar. I refrain from giving it a name
until more complete material may be at hand.
TURBONILLA (PYRGISCUS), species ?
Cat. No. 186851a, U.S.N.M., contains a badly-worn specimen from
Port Alfred (Coll. No. 218a). It is much smaller than the last one
referred to, and is probably a new species.