ACEPHALA

‖A‐ceph″a‐la (�), n. pl. [[NL., fr. Gr. �, adj. neut. pl., headless. See Acephal.]] (Zoöl.) That division of the Mollusca which includes the bivalve shells, like the clams and oysters; — so called because they have no evident head. Formerly the group included the Tunicata, Brachiopoda, and sometimes the Bryozoa. See Mollusca.