Risso, 1826
Description (shell):
Shell tall, sharply pointed, conical, with 16-20 tumid whorls. Sculpture of numerous spiral striae of varying proportions: three (or up to six) usually more prominent than others; sinuous growth lines may interact with spiral striae to give them a beaded appearance. Aperture small, angulate; outer lip crenulate. No umbilicus (T. communis-drawing).
Size:
Up to 55 x 16 mm, commonly 30 x 10 mm.
Colour:
Buff coloured with lighter striae; may have lilac tinge on base.
Animal:
Snout broad; cephalic tentacles short, cylindrical. Mantle edge with numerous pallial tentacles, short, often bifid or trifid on right, longer and more pinnate on left. A deep pallial groove crosses the floor of the mantle from the left, terminating below the right cephalic tentacle. Pallial tentacles and groove associated with filter feeding habit. Foot small; operculum small, circular and concave, with numerous marginal bristles.
Habitat:
Locally abundant sublittorally, down to 220 m, on soft bottoms; sometimes at ELWST.
Distribution:
Distributed from North Africa and Mediterranean to Lofoten Isles (Distr. T. communis).