(Linné, 1767)
Description (shell):
Broadly oval, about one and a half times long as wide. Shell valves smooth and glossy; gently arched, keel scarcely developed but beaks well-marked. Sculpture more distinct than in Tonicella marmoreus : very fine granulation dorsally, becoming rather pronounced marginally; growth lines conspicuous. Girdle marbled brown and white, densely covered with spherical granules, fringed with slightly flattened spines (T. rubra).
Size:
Up to 20 mm long.
Colour:
Shell valves pale buff to deep chestnut-brown, richly marbled with white.
Habitat:
Lower shore and sublittoral.
Distribution:
Not in the southern North Sea (Distr. T. rubra).