(Linné, 1771)
Description (shell):
Shell cap-shaped with recurved beak terminating in a small spire of one or one and a half whorls; slit-like hole opens on anterior slope just below beak, in dead shells an internal hemi-conical septum is seen below this opening (P. noachina-drawing).
Size:
Up to 7 x 5 x 4 mm.
Colour:
White-cream.
Animal:
Body whitish; foot oval, truncated at front end with 20-30 epipodial tentacles around its base. A bifid tentacle behind eyestalk at base of right cephalic tentacle. (P. noachina-animal).
Habitat:
In British waters confined to sublittoral rocky and stony substrata (especially those rich in sponges) between 20-165 m. Intertidal in high latitudes.
Distribution:
A circumpolar species which extends south to Portugal and the Mediterranean (Distr. P. noachina).