Circulus striatus

(Philippi, 1836)

Description (shell):
Shell small, flattened, semitransparent, glossy, with a low, obtuse spire and a very large umbilicus. There are 4-5 whorls, rounded in section, with deep sutures placed on the apical side of the periphery of each whorl. There are usually eight or ten (up to twelve) spiral ridges on the last whorl, 5-6 on the penult, 4-5 on the previous, the rest is smooth. The last whorl occupies 80-85 % of shell height and the base lacks ridges, but a further series of four or five appears on that part of it which lines the umbilical space. Other whorls exposed in that space also show ridges. The aperture lies in a prosocline plane, occupies about three quarters of shell height and appears nearly circular when the shell is held upright. The outer lip arises level with spiral ridge 6, 7 or 8 and shows a small peripheral bay and slight basal projection; it is crenulated by the ends of the ridges.

Up to 1.3 x 2.8 mm.


Narrow snout which is a little bifid at the tip and two long and delicate tentacles, each with a basal eye. Males have a slender, sickle-shaped penis. The foot is narrow with recurved anterolateral points. Whitish with opaque white speckles, the snout pinkish. Operculum with about 12 turns.

Muddy bottoms at about 30 m deep.

Probably absent from the North Sea. It is a southern species occurring from the Mediterranean north to Britain and Ireland.