The instance referred to is that presented by bivalve shell-fish.
The mother-of-pearl which lines some shells, both univalve and bivalve.
Flattened sideways and as hard as stone, no bivalve can resist it.
Many persons prefer it to the bivalve, when it is cooked properly.
Bivalve shells are said to gape when the margins do not meet all round.
A bivalve is said to be ...