Cockles are found from the Bering Sea to California. Their shells are medium size, slightly higher than long, somewhat triangular in shape. They are easily recognized by the prominent, radiating, ribs which originate at the hinge line and fan out to the outer shell margin and are evenly spaced on the exterior of the shell. The shells, which are light brown, completely close. Cockles have short siphons and, therefore, are rarely buried more than an inch or two in the substrate. Shallowly buried, they are easily harvested by sport diggers at low tide who pick them from the surface by hand or with a garden rake. They inhabit sand and mud beaches intertidally and subtidally to 50-60 feet. They have never been observed in large concentrations in Puget Sound, but are common and widespread. The cockle has a powerful muscular foot, which gives it a high degree of mobility. They have been observed moving along the bottom by springing with the foot. Each hop can cover two to three feet. They frequently enter the commercial harvest with butter and littleneck clams but are not important commercially. They spawn in the summer.