Shell small, ovate, perforate, semitransparent. There is no sculpture, except microscopical fine close growth-striae. Colour horny-fuscous. Epidermis very thin, faintly shining. Spire conical, a little lower than the aperture, outlines convex. Protoconch rounded, shining, and quite smooth. Whorls 5, the last large and globular, the spire-whorls somewhat rounded ; base convex. Suture well marked. Aperture ovate, somewhat oblique. Outer lip thin and simple. Columella arcuate, solid, thickened, and slightly reflected; a callus extends from the insertion of the outer lip to the columella, partially concealing the narrow umbilicus. Operculum horny, consisting of about 2 rapidly increasing whorls. Diameter, 2,3 mm. ; height, 2,75 mm.
Animal. Foot comparatively large, flat, and undivided ; tail abruptly rounded ; head produced into a retractile muzzle, emarginate anteriorly ; tentacles of medium length, expanding and uniting at the base so as to conceal the posterior portion of muzzle ; eyes immersed, and situate in the lower half of tentacles ; colour whitish throughout. Jaws forming 2 irregularly ovate objects, united by a narrow band ; they are dark in colour, and the surface, as it were, imbricate, with scale-like markings. Dentition. — The formula is 23 + 2+1 + 2+23. The teeth are arranged in numerous transverse curved rows, the rhachidian short and broad, with 11 minute cusps; the laterals elongated, with the apex somewhat expanded and curved inwards, the first armed with 6 or 7, the second with 7 or 8 minute denticles ; marginals about 23, having a single rounded cusp, and becoming shorter as they proceed outwards.
New Zealand: Inner Harbour, Napier; found in considerable numbers around the margin of a brackish pool ; type (F. Hutchinson, jun.) : Titahi Bay, Cook Strait.