Colus islandicus

(Mohr, 1786)

Description (shell):
Shell similar to Colus gracilis , differing only in minor detail. Protoconch bulbous, often of greater diameter than next whorl and set more obliquely on spire; whorls more tumid. Spiral striae often more pronounced, less than 40 on last whorl; triangular area of last whorl lacking periostracum relatively smaller than in Colus gracilis . Aperture with long narrow siphonal canal; (about 25 % of shell height), not markedly inclined to left; outer lip arises at level of spiral stria 10-12 on last whorl (C. islandicus-drawing).

Up to 150 x 50 mm.

White, with light horn-coloured periostracum.

Indistinguishable from that of Colus gracilis.

On soft substrata, from 10-3000 m.

A northern species extending south to Shetland and the north coast of Scotland (Distr. C. islandicus); subfossil shells may be encountered in more southern waters.