Shell length up to 25 mm, mean w/1 ratio 0.75, mean h/1 ratio 0.32. Shell ovate, symmetrical, cap-like with apex extending a little way outside the shell edge. Apex often eroded. Septum narrow, yellowish with a straight edge. Ground colour yellow to yellow-brown with black nearly horizontal or transverse lines across the shell. Where the lines cross they form obtuse triangles. Inside the shell is white-gray, muscle scars not prominent. Males significantly smaller than females and fewer males in populations. Operculum: Pale pink, horn at posterior margin orange-brown, fragile and rib relatively long.

Early authors treated S. bougainvillei as a separate species, but more recent¬ly it has been considered a synonym of S. porcellana. FRANC (1956) and STARMOHLNER (1970) used S. borbonica depressa to include both both S. bougainvillei and S. porcel¬lana in New Caledonia and Vanuatu. From 1984 - 1991, HAYNES used the name S. porcellana for the Fijian species when in fact she was referring to S. bougainvillei. In 1996, HAYNES described the differences in the reproductive anatomy of these two species and established that S. bougainvillei was a valid species endemic to the south Pacific islands. Both S. porcellana and S. bougainvillei are found in Vanuatu and New Caledonian streams and this has added to the confusion. Female S. suffreni have been mistakenly identified as S. bougainvillei, which they resemble, but S. bougainvillei females unlike S. suffreni have no spermatophores or spermatophore sac.

Fiji, New Caledonia, Vanuatu, (Samoa?). From a few metres from the sea to 3 - 4 km inland on rocks and stones in swift flowing streams.