testacea

A testaceous substance, something made of shell or shell-like material.

Noun obsolete, rare

From Latin testāceus (“covered with a shell”).

Any of various shellfish, especially those of the obsolete orders Vermes or Acephala, or the suborder Thecosomata.
- ANAIMONA, Aquatilia Exanguia, Bloodless Fishes, are divided into Mollia Soft Fishes without Shells; Crustata, those that are covered with thin pliant Shells; and Testacea, those which have thick, hard brittle Shells. -...
- The echinite family […] may be deemed characteristic of the chalk formation, affording of itself as many shells as the other testacea do. - 1829, Andrew Ure, A New System of Geology, page 285:
- […]to fancy, for example, that the testacea of the ocean existed first, until some of them, by gradual evolution, were improved into those inhabiting the land. - 1832, Charles Lyell, chapter I, in Principles of Geology...