Shell description. - The shell is triangularly ovate. It is solid and covered with a thin brownish periostracum. The shell exterior is glossy, generally purplish-white with darker bluish concentric bands placed randomly. The shell sculpture
consists of strong concentric ribbing, more prominent toward the ventral edge. The anterior dorsal margin is almost straight, and the posterior dorsal margin is only weakly convex. Both the anterior and posterior margins are equally rounded, and they are connected by a curved ventral edge. The umbones are blue in colour, pointed, curved inwards, and placed just about the midline of the shell and slanted toward the anterior. The lunule and escutcheon are large, well defined, and covered with strong concentric ribbing. The hinge line is white. The shell interior is glossy and smooth. The interior ranges from light to dark purple, and appears almost white at the margins. The pallial sinus is rounded, shallow, and about as deep as it is high. The two cardinal teeth in the right valve are disposed divergently at a right angle. The left valve has one anterior and one posterior lateral tooth, and the right valve has two anterior and two posterior lateral teeth.

Distribution. - Reeve (1854) mentions the type locality of this species as Australia. This species is harvested in Thailand (Rabanal et al., 1977) and has been reported from Pantai Beserah, Pahang, on the east coast of West Malaysia (S. K. Tan, pers. comm.).

Remarks. - Disjointed valves were commonly found deposited at the high tide mark during the survey. Live shells were less commonly observed.