Philine catena (Montagu, 1803)

The shell is internal, whitish transparent and squarish-oval in shape. The apex (top) of the shell is blunted and slightly sunken. The shell is slightly umbilicated. The opening of the shell is large and wide. The surface is covered by chainlike lines of pits connected by narrow groves.

The colour is cream to light brown with small brown dots on the surface. The head shield is blunt and does not have a middle groove.

The radula usually consists of about 30 rows of teeth with one outer lateral tooth and one inner lateral tooth on each side. The central (rachidian) tooth is absent. The outer lateral teeth are straight with rounded tips and a narrow base. The inner lateral teeth are curved with rounded tips and a broad base and the inner edge is denticulate. The three similar gizzard plates are angular and pointed at the ends. The male reproductive system has been illustrated as a sack-like penis chamber with a prostate that looked like a feather duster.

On fine sand from the intertidal inside tide-pools, under boulders on beaches, down to depths of 2000 m. Philine catena can be predated by flatfish.

Occurs in the eastern Atlantic, from Lofoten in Norway southwards along the entire coast of Norway, down to the British Isles, the Mediterranean Sea, and the Canary Islands.