Shell. A variable shell, but differs from that of C. gracilis in only a few points. The 7-8 whorls are more tumid, the sutures a little deeper; the apex is blunter; the apical angle may vary from 30-40° and reach 48° in young shells, for which reason the spire is a little cyrtoconoid. The ornament is like that of gracilis: there are 24-34 spiral ridges on the last whorl, 7-10 on the penult, 6-9 on the previous, and 5-7 on the upper whorls of the spire. The crossing of ridges and growth lines gives a delicate reticulation of the surface which is repeated in the periostracum which may be rather hairy, though hairs are often worn away.
The protoconch has 1.5-2.0 whorls, up to 2.75 mm across; the whorls are smooth, and form a short, insunk spiral with the same axis of coiling as the rest of the shell.
Aperture. As in gracilis, though the long axis may lie more oblique to that of the spire. The outer lip arises level with spiral ridge 8 or 9 on the last whorl. The siphonal canal may be relatively longer than in gracilis and lies more along the line of the apertural axis. There is often a more marked angle between outer lip and canal than in gracilis.
Colour. As in gracilis, sometimes with bluish or pinkish tinge.
Size. Up to 50 x 25 mm. Last whorl (plus canal) = 65-75% of total shell height; aperture = 50-55% of shell height; canal = 16-20% of total height.
Animal. Much as in gracilis. The eyes lie closer to the summit of the tentacles and these are longer and less flattened than in that species. The siphon also is relatively longer, and the anterior end of the foot less square.
Colour. Pale cream.
Geographical distribution. From the Mediterranean off southern Spain to Norway and Iceland. It extends through the Skagerrak and Kattegat to the Northern parts of the Sound, but is rare in these waters. Not common anywhere in the area but less in the cast Channel and southern North Sea than elsewhere. Habitat. Soft bottoms 30-2000 m deep.