
• (n. pl.) 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.
Found on
http://thinkexist.com/dictionary/meaning/acephala/
A·ceph'a·la noun plural [ New Latin , from Greek ..., adj. neut. plural, headless. See
Acephal .]
(Zoology) 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 Tu...
Found on
http://www.encyclo.co.uk/webster/A/17

The Acephala are the headless Mollusca with a bivalve shell.
Found on
http://www.probertencyclopaedia.com/browse/BA.HTM
No exact match found.