Diagnostic characters
Shell covered with periostracum concealing whorls and sutures. Spire low. Aperture large and nearly circular. Dark brown.

Other characters
The 2-3 whorls of this shell are tumid and marked with delicate spiral and growth lines. The periostracum is brown, the calcareous shell white or pinkish. Up to 10mm high, 10mm broad; last whorl equals the whole shell height, aperture occupies about 90% of it.
The animal has the same features as V, plicatilis but its flesh is white or yellowish, the mantle edge with many white points.
V. velutina is a circumboreal form, more frequent in the fauna of the British Isles than V. plicatilis, and occurring in most parts, though commoner in the north. It is sometimes found at extreme low water on rocky shores but is usually sublittoral and associated with such solitary ascidians as Styela, upon which it feeds (Diehl, 1956).
The animals breed in spring and the larva has been described by Lebour (1935a). It is an echinospira with a flat discoidal shell as in Lamellaria species, but the outer shell, instead of being stiff and hard as in that genus, is soft and gelatinous, lacks marginal keels, and in later stages of development becomes rather bloated. The velum has four lobes.
A further species of this genus, undata Brown, 1839, has been recorded alive from deep water off Shetland. Like V. velutina it has a shell with rather pointed spire, but the aperture resembles that of V. plicatilis in being clearly oval, not circular as in velutina. The shell is more heavily calcified and the periostracum is thinner than in those species, and it also differs in having more or less clear brown spiral bands.