The shell outline is variable, sometimes deformed owing to its habitat. Indeed some species as quoyi (Payraudeau, 1826), gaymardi (Payraudeau, 1826) and other ones were described of no taxonomic value. It has to be noted that the juvenile shell shape is more edgy, much for its back margin which is longer than the adult one, this last so looking a rounder look. The surface is sculptured and is made by thick radial ribblets and growth lines with granules where they cross. The shell background colour is dirty white, while its short and soft periostracum is brown and this is more evident on the ventral margin. The average meas¬ures are about 10 mm.

Habitat: this species lives on detrital rocky bottoms and/or into rock cavities and gorges , fixed to the substratum by its byssus. Found on Peyssonnelia polymorpha thalli and in Cladocora cespitosa colonies too. Distribution: very common all over the Mediterranean, where it is found at moderate depths too.