The brightly colored, fan-shaped shells of some scallops, with their radiating fluted pattern, are valued by shell collectors and have been used as motifs in art and design. The name «scallop» is derived from the Old French escalope, which means «shell».
Like the true oysters (family Ostreidae), scallops have a central adductor muscle, and thus the inside of their shells has a characteristic central scar, marking the point of attachment for this muscle. The adductor muscle of scallops is larger and more developed than that of oysters, because they are active swimmers; scallops are in fact the only migratory bivalve. Their shell shape tends to be highly regular, recalling one archetypal form of a seashell, and because of this pleasing geometric shape, the scallop shell is a common decorative motif.