Shell small , roundish, as a rule with cone-shaped, in most cases fairly small spire consisting of few whorls; smooth or spirally striated, uncolored; aperture of moderate size, more or less narrowed due to the parietal callus which frequently heats a tooth; columellar margin with 2 strong folds, below this the lower margin considerably recedes and forms a deep indentation. Outer margin more or less thickened, occasionally also with a tooth-like projection interiorly. An operculum absent.
Animal completely retractable into the shell; foot anteriorly broadened; head shield broad and short, bilobed, anteriorly somewhat indented, posteriorly with a median lobe, the lateral margins of which fold downward to form a channel; eyes showing through or absent. Jaws roundly triangular; radula fairly small, on either side with a row of terminally pointed and somewhat hook-shaped recurved plates; esophagus long; stomach muscular, without plates; the gill is a pleated lamella lying anterior to the heart; the pleural ganglia lie beside the cerebrale; the sperm duct is closed, with a prostate.