Shell stretched in form, surface crossed by very strong radiating spines ribs or tubercles sculpture (above all in the ventral zone), it is easily recognizable from its congenerous ones, due to its well defined sculpture. The anterior ear (really well defined even in the juvenile specimens) is much more developed than the posterior one and it is often covered with spines or nodules. We can often find small tubicolous Polychaetes, Scrpulides, Bryozoans and other tiny epibionts fixed to the surface. Thin radial striae are quite defined in the juvenile specimens too. Colouring pattern is dirty white, dark grey in the old specimens, inside of the valves is porcelain-as. The average measures reach 40-50 mm in length, sometime this shell can reach even 10 cm in length.

Habitat: this species lives in the littoral area among rocks and in the coralligenous or under some kinds of sponges, fixed to the substratum by its byssus but it can move quickly too.
Distribution: common enough all over the Mediterranean, it seems to be missing in the Black Sea.