Shell small, globose, fairly solid, polished, smooth, umbilicate. Sculpture consisting of very fine and close growth-lines, crossed by faint microscopical striae. Colour either uniformly brown with a few lighter blotches, or cinereous with radiate flexuous narrow brown bands, a series of triangular whitish spots revolving a short distance below the suture, and irregular-shaped white streaks issuing from the umbilicus; peristome light brown. Epidermis thin, transparent, shining. Spire low, depressed conoidal, lower than the height of aperture ; outlines convex. Protoconch small, with a comparatively large nucleus, of 1,5 smooth flattish whorls. Whorls 3,5, convex, the last, large in proportion; base convex. Suture lightly impressed. Aperture sub vertical, semilunar, inside dark brown. Outer lip convex, with a rather blunt edge. Columella sub vertical, thick and callous, curved below towards the basal hp. Inner lip strongly callous, triangularly produced over half of the umbilicus, and forming a thick brown and shining callus on the parietal wall. Umbilicus moderate, the outer half open. Operculum calcareous, paucispiral, with distant growth-lines and close spiral striae.
Diameter, 7,5 mm. ; height, 7,5 mm. (type).
Animal unknown.
Type in the Otago Museum, Dunedin.
Hab.—Auckland Harbour, dredged in Rangitoto Channel, type (T. F. Cheeseman) ; off Great Barrier Island, in 110 fathoms ; Snares, in 50 fathoms (Captain Bollons).
Remarks.—The specimens from 110 fathoms are white, semitransparent, occasionally with a few radiate brown bands. The inner lip is by far not so strongly callous, and leaving sometimes the umbilicus quite open.
Fossil in the Pliocene.