a. and sb. Zool. [f. prec.: see -ACEAN.]
A. adj. Of or pertaining to the TESTACEA; shell-bearing; chiefly applied to mollusks.
1846. in Worcester, citing Lyell.
1871. Lyell, Elem. Geol., ix. 119. Value of testacean fossils in classification.
B. sb. A member of the testacea; a shell-bearing invertebrate, esp. a mollusk.
1842. Brande, Dict. Sc., etc., Testaceans. Testacea.
1847. Webster, Testaceans (Zool.), marine animals covered with shells, especially mollusks; shellfish.