Как по Английски будет 双壳

adjective

(of a mollusc or other aquatic invertebrate) having a hinged double shell.

Примеры использования:

This makes brachiopods look superficially like bivalved molluscs (clams, oysters, etc.)

noun

An aquatic mollusc which has a compressed body enclosed within a hinged shell, such as oysters, mussels, and scallops.

Примеры использования:

Shell fragments of bivalves and gastropods are common in neogene shallow-water deposits.