1⁄2 to 1 inch in length. Shell thick, with 11 rows of neat, rounded, whitish, 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, usually found well out of water on the rock cliffs.
Genus Echininus Clench and Abbott 1942
Subgenus Tectininus Clench and Abbott 1942
Plate 19h
Southeast Florida and the West Indies.
1⁄2 to 1 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 multispiral. Lives well above high-tide mark on rocky shores. Be sure not to confuse with Nodilittorina tuberculata 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 15 confusing species on the west coast of America, most of which are found in Alaskan waters.
Moss Beach to Monterey, California.
4 mm. in length, light-brown, smooth. Suture slightly indented. Uncommon from shore to 15 fathoms.
Subgenus Nodulus Monterosato 1878
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).
