shell, cutting across the ribs. Lip of aperture with one or two swollen axial rings.
Rather thick, glossy, slightly curved shells; aperture minutely constricted; sculpture absent except for microscopic growth lines. The shells are larger, heavier and not as bulbous as those in the subgenus Fartulum.
Figure 37c
North Carolina to southern Florida.
About 4.5 mm. in length, glossy, cream-white. Smooth except for microscopic growth lines. Apical plug sunk in at the posterior end of the shell and with a sharp, horn-like projection. Aperture minutely constricted.
Subgenus Fartulum Carpenter 1857
Shells very small, about 2 mm. in length, fragile, smooth, except for microscopic growth lines; not swollen in the middle; and with a nonconstricted aperture facing to one side (oblique).
Figure 37f
Missouri Key, Florida Lower Keys.
1.5 to 2.0 mm. in length, fragile, translucent-tan with opaque-white mottlings. Not swollen in the center. Aperture oblique. Apex with a lopsided plug which has a single, weak spur. Found under flat rocks imbedded in tough, sticky marl.
Figure 37l
San Pedro to Lower California.
2.0 to 2.5 mm. in length. Smooth, except for fine, circular scratches. Shell stubby, slightly compressed laterally; aperture oblique; apical plug dome-shaped. Color translucent-tan to yellow-brown. Moderately common.
Figure 37j
Alaska to Lower California.
2.2 to 3.5 mm. in length. Smooth, except for fine, circular scratches. Shell elongate, round in cross-section. Aperture moderately oblique; apical
