(Montagu, 1808)
Description:
Shell thin and fragile. Faint radiating striations, visible with hand lens, and slightly bolder concentric lines. Anterior hinge line curving well above the horizontal when the posterior is vertical; 14-18 hinge teeth anteriorly, 6-10 posteriorly; lunule poorly defined, escutcheon strongly pouting. Margin of shell smooth (N. tenuis-drawing).
Size:
Up to 10 mm long.
Colour:
Shell white or grey, periostracum glossy, greenish-yellow to brown.
Habitat:
On muddy deposits, offshore, perhaps to the edge of the continental shelf.
Distribution:
Not in the southern North Sea (Distr. N. tenuis). Distribution circumboreal; present in the Mediterranean.