Shell turreted, moderately solid, costellate. Sculpture consisting of rather distant axial plications, 12-15 on the penultimate whorl, slightly arcuate, prominent or subobsolete, crossed by numerous spiral cords, mostly visible only on the lower whorls; base with a double ridge on its periphery, the lower one much stronger and separated by a groove from the upper ridge ; the latter margins the suture of the last whorl; the lower ridge enters the aperture, forming with the outer lip a parietal channel; base with distinct growth-lines. Colour blackish-purple or brown, often with a brown or whitish coating. Spire very high, conic, about three times the height of the aperture; outlines straight. Protoconch eroded. Whorls about 12, regularly increasing, convex ; base concave. Suture impressed. Aperture ovate, produced into a very short, open, oblique, and truncated canal. Interior blackish-brown. Outer lip convex, straightened above, very little thickened and expanded, sharp, with an interior orange margin. Columella light brown, slightly concave, smooth, base obliquely truncate. Operculum normal.
Diameter, 10 mm. ; height, 29 mm. Angle of spire, 23°. Dentition.—Hutton, T.N.Z.I., xv, 122, pl. 14, f. D. Type in the British Museum.
Hab.—Bay of Islands, type (Dieffenbach). Common in the North Island; not found south of Banks Peninsula. Fossil in the Pliocene.