In the juvenile specimens the valves narrowing is more defined (in the ventral zone). In the different growth stages this species does not change its outline very much, and also the adults do not show a special morphological variety. The valves have got a sculpture made by thin radial little ribs and by fine concentric striae giving to the shell a finely reticulated sculpture. The shell is dirty white in colour, with a thin homogeneous periostracum yellowish or light brown in colour. It is recognizable from B. pectunculoides, besides the bigger sizes, also since it has got a more stretched outline with the ventral margin less convex. The average measures are abt. 7-8 mm.

Habitat: it is more common on muddy bottoms.
Distribution: common all over the Mediterranean even in remarkable depths.