(Linné, 1758)
Description (shell):
Shell large, solid, glossy, with a tall pointed spire and an angulated profile. The shell has 7-8 whorls meeting at shallow sutures. Last whorl is large and occupies about two thirds of shell height. The whole surface is covered with small spiral ridges, but up to ten on the last whorl and two on each whorl in the spire are much bigger than the others and are also nodose. There are varices at 120° intervals. Each varix consists of a prominent swelling across the whorl with a sharp, undercut edge on the side facing down the spiral. The aperture occupies a little more than half of shell height. It is a broad oval, pointed above and below, the siphonal canal is short and open. The inner lip spreads at its base over an umbilical groove, and, more adapically, widely over the surface of the last whorl. Columella fluted with ridges, one large one adapically. Outer lip with paired short ridges internally.
Size:
Up to 330 x 180 mm.
Colour:
White with brown blotches, especially near sutures, on the inner folds of the outer lip, and at the base of the columella.
Animal:
The flesh is reddish with many scattered brown spots. Each tentacle has two longitudinal black lines.
Distribution:
A southern species ranging between the Mediterranean and the extreme southern parts of the British Isles (Distr. C. lampas). It is reasonably common as far north as the southern parts of the Bay of Biscay but beyond that is sporadic in its occurrence.