Kelp scallop shells. Illustration of the shells of kelp scallops (Leptopecten latiauratus), small saltwater clams in the family Pectinidae. This species is also known as the wide-eared scallop, broad-eared pecten and the kelp-weed scallop. It occurs off the coast of California and Mexico, to depths of 250 metres. Shells of bivalve molluscs such as clams consist of two articulating parts, or valves.