(Linné, 1767)
Description:
The white body may reach a length of 32 mm, flattened, fragile, glistening and translucent, with white or acid-yellow subepidermal glands in the ample but frail mantle skirt. The upper surface of this skirt bears sparse, soft, low, conical tubercles, while the under surface exhibits a fine white tracery of spiculose markings. In a rare northern variant, the whole body is tinged with yellow. There are up to five (rarely seven) tripinnate gills. The lamellate rhinophores issue from low, crenulate, pallial sheaths. The oral tentacles are short, broad and flattened.
Habitat:
This northern species feeds upon encrusting slime-sponges, especially Halisarca dujardini.
Distribution:
It has been recorded down to 800 m from the Arctic Sea to the Mediterranean Sea and from both seaboards of the USA (Distr. C. laevis).