Cockle

Cockle, bivalve mollusk (order Eulamel libranchia) with cupped shell ornamented with radiating grooves. Cockles live buried in mud or sand, in shallow water, and dig themselves in by means of a muscular foot that can be protruded between the shells. There are numerous species along the coasts of North America ranging in size from the 4-in (10.2-cm) giant Pacific egg cockle to 1/4-in (0.6-cm) cockles. The common cockle of Europe is edible.