(Linné, 1758)
Description (shell);
Shell almost circular; inequilateral, umbones small but distinct, just anterior to midline. Dorsal margin gently convex posteriorly, deeply concave immediately anterior to umbones, with a highly arched junction with anterior margin. Lunule heart-shaped, as broad as long; escutcheon poorly defined. Sculpture of numerous fine concentric ridges, surface smooth to touch. Growth stages clear. Three cardinal teeth in each valve; a short, rounded knob in front of the interior teeth of the left valve engages in a shallow pit in the right. Adductor scars and pallial line distinct, pallial sinus deep, narrow, U-shaped, extending anterio-dorsally well into the anterior half of the shell (D. exoleta).
Size:
Up to 60 mm long.
Colour:
White, yellowish, or light brown, with irregular rays, streaks, or blotches of darker brown or pinkish brown. Inner surfaces glossy white.
Animal:
Pale yellowish, the mantle fringed with white lashes. The siphons are short and united. The large foot is white and axe-shaped.
Habitat:
Burrowing in muddy gravel or shell-gravel, from the lower shore to about 100 m.
Distribution:
Distributed from Norway to the Mediterranean and West Africa (Distr. D. exoleta).