(Linné, 1758)
Description (shell):
Shell solid, with five or six slightly tumid whorls; sutures shallow, in some specimens upper whorls may be flat-sided or even coeloconoid. Spire prominent, pointed, more so in young shells, though last whorl may occupy up to 85 %, of shell height. Shell may appear smooth, especially in older specimens, but has prosocline growth lines and numerous, slight spiral ridges; latter may be strap-like on last whorl. Aperture ear-shaped, outer lip arising tangential to last whorl; inner lip thick, reflected over base of columella. No umbilicus or umbilical groove (L. littorea-drawing).
Size:
Up to 32 x 25 mm.
Colour:
Generally black or dark grey-brown, often lighter towards apex, with heavier pigmentation between spiral ridges; occasional red, orange, or white individuals occur. Columella region white, outer lip with a darkly pigmented band internally, contrasting with lighter pigmentation of throat.
Animal:
Cephalic tentacles rather flat and broad, with many transverse black stripes and, ventrally, a single longitudinal line. Foot and operculum of typical littorinid pattern.
Habitat:
Common on all but the most exposed rocky shores; mainly intertidal, the upper range increasing with exposure, but extends sublittorally to 60 m in the north. In sheltered conditions it may he found undertaking feeding excursions over muddy shores; tolerant of brackish water.
Distribution:
Distributed from northern Spain to White Sea. On all British coasts, Dutch coast and Helgoland, though rare or absent in Isles of Scilly and Channel Isles (Distr. L. littorea).