Shell length to 11 mm; left valve slightly more convex than the right. Sculpture: numerous, strong, close-set radial ribs, profusely scaled, auricles profusely ridged and scaled; interstices slightly wider than the ribs with a radial row of sharp prickles. Colour: bright orange, internally orange. Habitat: sand, to 35 metres. Distribution: Great Barrier Reef, north Queensland.