(Deshayes, 1823)
Diagnosis: Shell hyaline, triangular, brown. Brown color especially noticeable along centre of dorsal side. Ventral side vaulted. Eighteen strong, linear ventral ribs composed of rows of tubercles. Dorsal side slightly flattened, with well-developed central and weaker latero-dorsal ribs; lock ribs small. Lock area, main tubercle and link well-developed. Lunar tubercle relatively small, minor tubercle strongly reduced. Extremely small second lock mechanism marked by little curve on lateral border of dorsal side. Ribs on dorsal side. Lateral lines nearly straight, flanks well pronounced. Lateral spines only slightly bent, sharp and hooked; gutter corners small. Caudal spine and caudal spine mark absent. Dorsal lip with notch, gutter, pronounced constriction, and inner hump. Abrupt lateral constriction in rostrum gives rise to tubercle distally, separated from rest of dorsal side. Ventral lip moderate in size with normal median depression. No lip flaps; moderate lip bellies and well-developed lip shoulders. Moderate hump present but no inner hump; rostrum projects anteriorly. Protoconch II area projecting moderately, provided with a relatively broad caudal joint. Shell length 4.6 mm, width 4.2 mm.