Length, 7 mm; diameter, 2.5 mm (holotype).

Shell: fusiform-ovate, apex tapering; with fine axial threads; cream. Spire: protoconch of two smooth, blunt whorls; teleoconch Of five somewhat inflated whorls; suture distinct. Sculpture: numerous threadlike axial threads extending from the suture to the base, with subequal interspaces; spiral sculpture of a constriction in front of the suture forming a subsutural band. Aperture: ovate, wide; sinus conspicuous; outer lip thick but not varicose; smooth within. Color: cream to light yellowbrown.

The narrow axial ribs, reminiscent of those of a rissoinid, and yellow-brown color distinguish these shells from others in the genus. Derivation of name: Rissoina, genus of mesogastropods; formis from the Greek — in the form of. Refers to the superficial resemblance to Rissoina.

Hawaii. Type locality: Kepuhi Point, Oahu, at the base of a cliff, depth 60 m.
Type-material:
Holotype: B. P. Bishop Museum No. 9812. Paratypes: Australian Museum; British Museum (Natural History); U. S. National Museum; R. $alisbury collection.