Up to 75mm long, 75mm high, 45mm across, rounded-triangular, somewhat oblique. Up to 50 faint and smooth flattened radial ribs, crossed by fainter concentric striations and more marked growth lines, which may give a faint decussate appearance. In the left valve the anterior lateral tooth may have subsidiary toothlets below it and the posterior lateral may be reduced or absent. Inside crenulate along the ventral margin, the crenulations not matching the ribbing as in the other genera, and much coarser than the ribs, inside grooved to a greater or lesser extent, usually about 1/6 of the way in. Periostracum present except in some juveniles where it is so thin it is easily abraded, thin and tightly adherent with a faint lustre or matt, with microscopically fine concentric wrinkles, olive or dark brownish black. Shell white with pale red-brown mottling on the outside, most pronounced in small specimens, inside may have brown blotches around the muscle scars. Animal yellowish white with a pinkish mantle, foot long and powerful, pointed at the end, white under a pinkish film. Edible.
- The surface of the shell is smooth; the ribs do not project
- The crenulations along the inner margin do not match the ribbing
Living in sand, muddy sand, shell gravel and maerl 10-100m. Active burrower.
Distributed from the Norwegian Sea to the Iberian Peninsula and into the Mediterranean.