Shell somewhat cask-shaped, short and obese, conspicuously swollen in the middle, tapering rapidly toward both ends: convex on all sides, though less dorsally. Aperture with simple, thin periostome; anal orifice comparatively large, with simple edge, contracted by a wide circular callus or ledge just within the opening.

Type species: Dentalium ovulum Philippi, 1844; by subsequent designation, Pilsbry & Sharp, 1897.
Diagnosis. Shell more or less swollen near the middle or anteriorly, contracting towards the aperture as well as tapering posteriorly. Apex simple with a wide circular callus or ledge within.

Mediterranean, North Atlantic, North Pacific, California.