Bivalve, consisting of two valves or divisions.

Blotched, spotted in an irregular way.

Blunt, obtuse, opposed to acute.

Borer, a piercer.

Brinded, streaked.

Bulging, gibbous, swollen out.

Bullate, of a blistered appearance.

Byssus, a beard, common in the Mytilus and Pinna.

C.

Calcareous, relating to lime, of a limy nature.