Crossword clue: a class of mollusca including all those that have bivalve shells, as the clams, oysters, mussels, etc.
2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
lamellibranchia
15 letters
web-def
oysters; clams; scallops; mussels
A class of Mollusca including all those that have bivalve shells, as the clams, oysters, mussels, etc.