Shell conical, elevated, imperforate, rather thick, solid, spirally lirate. Sculpture consisting of fine and distant spiral lirae, 6 to 7 on the penultimate, 12 to 16 on the body whorl, crossed by fine close growth-lines. Colour dark-bluish or greenish-black, sometimes with a purplish shade. Epidermis dull, not very easily rubbed off. Spire elevated conical, apex acute or obtusely rounded, sides flatly convex. Protoconch small, conic, of about 2 smooth and convex whorls, mostly eroded. Whorls about 6, very slightly convex, body-whorl subangular at the periphery ; base very slightly convex. Suture slightly impressed. Aperture rounded quadrate, oblique, less than half the total length of the shell, slightly iridescent and lirate within. Outer lip convex, subangled at the base, narrowly black-edged, bordered by a series of short fine sulcations, beyond which there is a porcellanous thickening. Columella sub vertical, slightly arcuate, rounded, covering the umbilicus above ; parietal wall with a very thin whitish callosity.
Diameter, 9,5 mm. ; height, 11,5 mm.
Hab.—Throughout New Zealand, mostly on seaweeds. Fossil in the Pliocene and Miocene.