Pecten maximus, common name the "great scallop" or "king scallop", is a species of scallop, an edible saltwater clam, a marine bivalve mollusk in the family Pectinidae. This is the type species of the genus. This species may in fact be conspecific with Pecten jacobaeus, the "pilgrim's scallop", which has a much more restricted distribution. 
The oil company Royal Dutch Shell derives its highly recognizable logo from this species.
Live individual of Pecten maximus
on the right, next to Ostrea edulis