3.0 mm. in length by 1.0 mm. in diameter, opaque-white, with 20 to 30 strong, axial rings, the last 3 or 4 being quite large.
Bonefish Key, Lower Florida Keys.
Shell similar to C. floridanum, but with about 14 very large, sharp axial rings.
Figure 37g
Monterey to Lower California.
2.0 to 3.0 mm. in length. With 30 to 40 moderately developed, evenly spaced, rounded or squarish axial rings. Lip of aperture slightly thickened. Color a glossy, olive-brown.
Figure 37h
San Diego to Lower California.
About 3 mm. in length, usually with 18 to 24 moderately developed, evenly spaced, rounded or squarish, axial rings. Lip of aperture usually heavily developed in adults. Color tan. The number of raised rings varies from specimen to specimen, often in the same locality, and diligent search will usually bring to light any number desired. Extremes have been unwisely named (15 rings—C. grippi Bartsch; 17 to 19 rings—C. licalum Bartsch, and 19 to 22 rings—C. diegense Bartsch). Figure 37h is the holotype.
Subgenus Micranellum Bartsch 1920
Shells 3 to 7 mm. in length, opaque, with numerous, fine, closely packed, axial rings. About 8 Eastern Pacific and perhaps half a dozen Western Atlantic species in this subgenus.
Figure 37d
Cape Cod south to North Carolina.
About 2 mm. in length, translucent-tan and glistening when alive; chalky-white when dead; with about 25 to 30 fine, closely set axial rings. Apex with a dome-shaped plug.
Figure 37m
Monterey to Lower California.