(Pennant, 1777)
Description (shell):
Shell thin, subtriangular and tumid. Sculpture of numerous radiating ridges, pronounced near margins, with equally numerous concentric grooves, giving a decussate effect. Growth stages clear. Lunule elongate, lanceolate, not clearly defined but distinctly pigmented. Escutcheon scarcely discernible. Three cardinal teeth in each valve. Adductor scars and pallial line distinct, pallial sinus small, U-shaped; inner shell margin finely crenulate. Superficially resembles a species of Parvicardium , but examination of the hinge teeth will prevent confusion (T. ovata-drawing).
Size:
Up to 20 mm long.
Colour:
White, light yellow, or pale brown, often with streaks and blotches of pink, chestnut, or light purple. Periostracum thin, indistinct. Inner surfaces white, glossy.
Animal:
The foot is large and tongue-shaped, adapted in burrowing. The siphons are of equal length, cylindrical, short and united, save at the tips.
Habitat:
In sand and gravel; offshore, perhaps to the edge of the continental shelf.
Distribution:
Widespread in the North Sea; distributed from Norway to the Mediterranean and Cape Verde Islands (Distr. T. ovata).