Gibbula tumida

(Montagu, 1803)

Description (shell):
Shell solid, cyrtoconoid, with stepped profile of six to seven slightly tumid, flat-shouldered whorls meeting at well-defined sutures. Sculpture of fine prosocline growth lines traversing spiral grooves and ridges. Umbilicus open and deep in young specimens, occluded by inner lip with age, and in larger shells appearing as an oval opening or small chink (G. tumida-drawing).

Up to 9 x 10 mm.

Light fawn with broken brown bands across whorls; usually with greenish-blue iridescence.

Body similar to Gibbula magus , snout not so papillate, sides of foot more so.

Sublittoral only; on Laminaria , and down to 1200 m on stones on sandy-muddy bottoms.

A northern species extending south from Iceland and north Norway to British, Irish, French, and Iberian coasts. Also found off Helgoland (Distr. G. tumida).