‖ testacea, n. pl.
(tɛˈsteɪʃ(ɪ)ə)
[L., neut. pl. of testāce-us adj., consisting of testæ, i.e. tiles, shells, etc.; also, covered with a shell: see -acea.]
† 1. Testaceous substances, as limestone, chalk. Cf. testacye. Obs. rare— 1.
| 1743 Lond. & Country Brew. iii. (ed. 2) 241 Chalk and other Testacea will answer the same, but not so well. |
2. Zool. A name for various groups of invertebrate animals having shells (excluding Crustacea). spec. † a. (a) used by Linnæus to designate his third order of Vermes, comprising the shell-bearing molluscs; (b) by Cuvier applied to the shell-bearing molluscs of his class Acephala. (Obs.) b. In present use, (a) A suborder of pteropod molluscs including all having calcareous shells, otherwise called Thecosomata; (b) an order of Protozoa having shells, with apertures through which the pseudopodia are protrusible.
| 1828 Stark Elem. Nat. Hist. II. 4 In the last edition of his Systema Naturæ, Linnæus,..in the third and fourth divisions of his third order, Testacea, places those possessed of shells. 1830 Lyell Princ. Geol. I. 52 Soldani..explained that microscopic testacea and zoophytes inhabited the depths of the Mediterranean. 1860 Hartwig Sea & Wond. i. 11 Pholades and Lithodomas are marine testacea, that have the power of burying themselves in stone. 1888 Rolleston & Jackson Anim. Life 905 The Amœbina may be classified as..: 1. Nuda s. Gymnamœbæ: devoid of a test... 2. Testacea s. Lepamœbæ: a test either chitinoid..or composed of chitinoid or siliceous plates cemented together. |