[2] This slug, like others in the family, has a small shell, which is situated towards the rear of the animal.

It has a small ear-shaped, external shell, less than 1 cm long, at the tail end of the mantle.

[3] This species is common along the western Mediterranean, along the European Atlantic coast and throughout Great Britain apart from northern Scotland.

[5] It also occurs as an introduced species in southern Australia, New Zealand[6] and North America (where it is called the earshell slug).

The distribution data for the United States, (Oregon, Wisconsin) and Canada (British Columbia, Nova Scotia) are incomplete.