Bible Dictionaries
Acephala

Webster's Dictionary

(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.

Bibliography Information
Webster, Noah. Entry for 'Acephala'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​a/acephala.html. 1828.