Any mollusc belonging to the taxonomic class Bivalvia, characterized by a shell consisting of two hinged sections, such as a scallop, clam, mussel or oyster.
A pericarp in which the seed case opens or splits into two parts or valves.
A hard clam (Mercenaria mercenaria) that is larger than a countneck, littleneck or topneck but smaller than a quahog.