CommonDistributed from the north of Norway south to the Mediterranean.
Lives attached to stones or other shells by a calcified byssus through a hole in lower valve. Filter feeds phytoplankton,
- Upper valve has three distinct muscle scars
Fragile shell up to 6.5cm in length. The outside is white, sometimes tinged with pink, in colour. The inside is a similar colour but pearly in appearance. The surface has a 'scaley' sculpture.