15mm. Steeply conical, robust, orifice much nearer anterior than posterior end, base conspicuously arched; radial ridges stronger than concentric ridges, noduled al intersections; margin corrugated; internal rim of orifice straight-edged posteriorly. White with reddish or brown rays. Habitat: intertidal among rocks and stones.

Diodora ruppelli (Sowerby, 1834). Length, 20 mm; diameter, 13 mm; height, 8 mm. Shell: conical, convex; apex decidedly anterior; fissure tri-cleft; margin thick and crenulate; with numerous fine nodular ribs; white splashed with black. Sculpture: 25 to 30 equally spaced ribs radiating to the margin with interspaces of equal diameter; spiral cords of lesser diameter crossing the ribs as scabrous belts. Color: white with triangular black marks.
Shells were first reported on Oahu in 1962 from the reef near the entrance to the Pearl Harbor channel; specimens have since been recorded at depths to 15 m.
D. ruppelli was described from the Red Sea and apparently occurs throughout the Indo-West Pacific.