Skenea serpuloides

(Montagu, 1808)

Description (shell):
Shell small, thin and glossy with three to four tumid, rapidly expanding whorls. Last whorl constitutes most of shell; adapically smooth, as are preceding whorls, underside enhanced by sharp spiral ridges and grooves. Aperture almost circular, with complete peristome; inner lip not reflected over umbilicus, which is wide, revealing underside of spire.

Size up to 1.5 x 1.2 mm.

White or colourless.

Cephalic tentacles broad and flat basally, fringed with sensory papillae; an additional tentacle, the postoptic, behind right cephalic tentacle. Papillae also on mantle edge and epipodial tentacles. Foot with anterio-lateral tentaculate extensions. Operculum polygyrous (about six turns), transparent.

On rocky shores among weeds and detrital sediments at LWST; sublittoral on gravelly and shelly sand down to 50 m.

A southern species extending north to the British Isles where it has been recorded off the west coast of Ireland, south-west England, and North Sea coast as far south as Scarborough (Distr. S. serpuloides). Patchy distribution may result in part from collectors overlooking these small shells.