Brittle shell up to about 2.5cm in length. Colour white or pink often with patches/rays of purple or red. Inside similarly coloured. Sculpture of fine concentric ridges and up to about 20 sharp ridges running towards the hind margin.
- No lateral teeth
- About 20 ribs radiating from the umbones to the back of the shell
- Slightly gaping at each end
Burrows in muddy or fine sand
North Sea to the Iberian Peninsula and into the Mediterranean