Rv depressed and almost flat. Outline irregular, generally suboval to subcircular. Pachydont hinge - a row of blunt teeth. Sculture of short spines more pronounced towards the margin where they are concentrically lamellate. More prominent spines on the left side of the valve.
Pallial line has no sinus.
Study of the early development of the Japanese jewel box Chama japonica showed that pediveligers initially attach to the substratum with a byssal thread. The habitat of C. pacifica off the coast of Israel consists of bare, rocky outcrops of kurlar, a submerged aeolic sandstone, at depths of 12-15m. 88 years after its first recording from off Alexandria, the existence of thriving viable populations off the coast of Israel confirm that it is now firmly established in the Mediterranean. Some members of the family are known for their decorative shells and have been adequately studied from the perspective of aquaculture. Ritrovamenti lungo le coste israeliane.