Shell description

The thick shell is external and white in colour, usually with an elongate oval shape. The opening is narrow, but extends the length of the shell. The top of the shell (apex) is sunken and involute. The shell is not umbilicated. The shell has a pattern consisting of spiral grooves and growth lines, where two of the growth lines are very prominent. The length of the shell ranges between 2–5.4 mm.

Animal description

The body is white in colour, and the head shield is lobed towards the back and there is no middle line. There are no side extensions of the foot (parapodial lobes) and no extension of the mantle under the snail (pallial lobe). The larval kidney is not visible trough the shell.


The radula consists of 11 rows of teeth, with two to three outer lateral teeth and one inner lateral tooth on each side and one central (rachidian) tooth. The outer lateral teeth have a curved tip and a broad base, and a smooth outer edge. The inner lateral teeth are curved with a broad base; the outer edge is smooth whereas the inner edge carries coarse denticles. The central tooth is denticulate. This species has jaws. The gizzard is cylindrical and not surrounded by muscle fibres, and holds three equal elongate bean shaped plates with raised fields on the dorsal surface. This surface has a pattern of grooves radiating from a central peak; the underside of the plate has a net-like pattern of pits. The foregut carries a crop with no apparent folds. The male reproductive system consists of a flat, white penis chamber that narrows towards the genital opening; the prostate is clearly separated from the penis chamber by a thinner yellowish prostatic tube.


Occurs at depths of 18–68 m, on muddy soft bottoms (Lemche 1956, Høisæter 2009).

Geographical distribution

Occurs in Svalbard and along the Norwegian coast north of Kjosen near Tromsø (69°35’ N). This species has also been found in the Hurry Fjord, Greenland (Lemche 1956, Brattegard & Holthe 2001, Høisæter 2009).


Brattegard T og Holthe T (2001). Distribution of marine, benthic macroogranisms in Norway. Research report for DN-2001-3. Directorate for Nature Management.

Høisæter T (2009). Distribution of marine, benthic, shell bearing gastropods along the Norwegian coast. Fauna Norvegica 28: 5-106.

Lemche H (1956). The anatomy and histology of Cylichna (Gastropoda Tectibranchia). Spolia Zoologica Musei Hauniensis 16: 1-278.