‖ acephala, n. pl. Zool.
(əˈsɛfələ)
[late L. acephala, a. Gr. ἀκέϕαλα adj. neut. pl. = headless (sc. animalia).]
Name given (by Lamarck) to one of the two great divisions of Molluscs. The sing. is supplied by acephal or more commonly acephalan.
| 1847 Carpenter Zool. §876 The Conchiferous Acephala, with scarcely an exception, have bivalve shells. 1863 Lyell Antiq. Man xxii. 442 A greater number of acephala or lamellibranchiate bivalves could be identified with living species than of gasteropods. |