download pdf

RISSOIDAE US
34 to 1 inch in length. Shell thick, with 1 1 rows of neat, rounded, whit-
ish, evenly spaced beads on the last whorl. Columella grooved; umbilicus a
narrow, oblique slit. Color of outer shell ash-gray. Interior dark-tan. Operculum
paucispiral. One of the commonest West Indian littoral species, usu-
ally found well out of water on the rock cliffs.
Genus Echininus Clench and Abbott 1942
Subgenus Tectininus Clench and Abbott 1942
Echininus nodiilosus Pfeiffer False Prickly-winkle
Southeast Florida and the West Indies.
Plate i9h
V2 to I inch in length. Base of shell squarish. Whorls with 2 spiral,
carinate rows of sharp nodules in addition to 2 or 3 rows of smaller, blunt
nodules. Columella not shelved. Color grayish brown. Operculum multi-
spiral. Lives well above high-tide mark on rocky shores. Be sure not to
confuse with Nodilittorina tuberciilata whose beads are lined up axially one
under the other.
Superfamily RISSOACEA
Family RISSOIDAE
Genus Cingula Fleming 1828
Extremely small shells, conic-ovate; aperture round, peristome complete;
whorls moderately rounded. Nuclear whorls smooth. Umbilicus slit-like.
There are about 1 5 confusing species on the west coast of America, most of
which are found in Alaskan waters.
Cingula montereyensis Bartsch Monterey Cingula
Moss Beach to Monterey, CaHfornia.
4 mm. in length, light-brown, smooth. Suture slightly indented. Uncommon
from shore to 15 fathoms.
Subgenus Nodulus Monterosato 1878
Cingula kelseyi Bartsch Kelsey's Cingula
San Diego to Lower California.
2 mm. in length, translucent-white, with microscopic spiral striations and
fine lines of growth. There are 4 other species in this subgenus which are
found in Alaska (C. asser Bartsch, C. kyskensis Bartsch, C. palmeri Dall and
C. cerinella Dall).