The rough cockle has a thick shell with 18-22 bold ribs and almost squared off grooves running from hinge to lip. These ribs show on the inside as well as the outside. They can grow up to 9cm (31/2 “) in length on muddy sand and gravel, from the lower shore into the shallow sublittoral from the southern part of the North Sea only, ranging south to the Mediterranean and north-west Africa. They are off-white, yellow, or light brown, often in concentric bands of different shades. The inside is glossy white. The siphons are quite long, and the foot is long and cylindrical. As wth clams, cockles should be thoroughly soaked for a couple of hours before consumption to clean them.