Mulina cleryana (d’Orbigny, 1846) - Puerto Rican Surf Clam

Up to 3.75 cm long, slightly inequilateral ( beaks very slightly anterior to midline). White, cream, light brown or grey in color (or mixtures thereof). The shell is thicker than in Mactrellona iheringi and the umbonal region is higher, each valve thus being more convex. The posterior region bears a distinct radial ridge. The external surface is smooth except for concentric growth rings and the inside is shiny. The right valve bears 2 cardinal teeth, 2 anterior laterals and 2 posterior laterals. The left valve bears 3 cardinals, 1 anterior lateral and 1 posterior lateral. The 2 anterior cardinal teeth form the characteristic V-shape and the 3^rd one (which is very weak and often broken) is just behind them. Again there is a prominent chondrophore. The pallial sinus is not as well developed as in Mactrellona iheringi and fails to reach the midline. The Periostracum is brown and fairly thick. This species is very common.