Scallop  (Pecten ), a well-known bivalve, one of those with a single muscle closing the shell. The valves are fan-shaped, the left often more or less flat, the right more markedly arched; both are marked with sinuous radiating ridges, to which the name pecten (Lat. “a comb”) refers. The hinge-line is without teeth, and is extended laterally in two ears. The small finger-shaped foot is usually marked with bright orange or red color. The scallops are widely distributed in all seas, at depths of three to forty fathoms.