Shell minute, globular, rimate, smooth, translucent, and polished. The only sculpture consists of microscopic growth-lines. Colour light yellow. Spire short, with a blunt apex, very little higher than the aperture ; outlines convex. Protoconch small, depressed, flatly convex. Whorls 3, convex, rapidly increasing, the last volution occupying about four-fifths of the whole height; base rounded. Suture deep, sometimes deeply channelled on approaching the mouth. Aperture rotundly ovate, angled above. Peristome continuous, very little callous, edge rather blunt. Columella subvertical, slightly arcuate. Inner lip a little reflexed, and producing an umbilical chink. Operculum unknown.
Diameter, 1 mm. ; height, 1,25 mm.
Hab.—Bounty Islands, in 50 fathoms (Captain Bollons).
Remarks.—Nearly allied to R. micans, Webster, which, however, has 3,5 to 4 whorls, and is much less globose ; specimens from Hauraki Gulf measure 1,1 mm. by 1,5 mm.