class Crustacea, Crustacea - class of mandibulate arthropods including: lobsters; crabs; shrimps; woodlice; barnacles; decapods; water fleas

mussel shrimp, ostracod, seed shrimp - tiny marine and freshwater crustaceans with a shrimp-like body enclosed in a bivalve shell

class - (biology) a taxonomic group containing one or more orders