Rissoella globularis

(Forbes & Hanley, 1853); Forbes & Hanley, 1853 ex Jeffreys ms.

Description (shell):
Shell small, transparent, smooth; more globular than Rissoella opalina , with three or four tumid, rapidly expanding whorls; sutures deep; breadth equal to or greater than height. Aperture pear-shaped, columella not straight as in R. opalina , peristome may project clear of last whorl; inner lip borders deep, round umbilicus.

Up to 1 x 1 mm.

White, nacreous, with dark viscera showing through in live shells; dark spots on mantle not conspicuous.

Short tentacles each with an eye behind the base. Colour pale with dark brown markings.

On fine red weed and in coralline rock-pools near LWST; not common.

Distributed along Atlantic coasts from France to northern Norway; British records confined to Shetland and north-west Scotland (Distr. R. globularis).