Rissoella sp. cf. confusa confusa Ponder and Yoo, 1977. Length, 1 mm; diameter, 0.5 mm. Shell: minute, ovate; umbilicate; thin, transpar¬ent. Spire: protoconch of about one whorl, not distinct from teleoconch; teleoconch of two whorls, convex; suture impressed. Sculpture: microscopic growth striae on an otherwise smooth and glossy surface. Aperture: ovate; outer lip thin; columellar callus raised, forming a ridge next the umbilical shelf; umbilicus narrow, short, deep. Operculum: ovate; with a peg. Color: semitransparent, glassy. Animal: black, spotted with chrome yellow; anterior margin of foot bilobed; head lobes and cephalic tentacles about the same length.
These minute gastropods are common in frondose algae in tide pools and on fringing reef flats. Adults are sometimes found in the plankton where they may appear traversing the water column on mucous threads produced by the pedal gland of the foot.
The shells and animal are similar to those of R. confusa confusa described from Lizard Island, Queensland, and found also in the Solomon Islands and New Caledonia (Ponder and Yoo, 1977).