thecophora

from The Century Dictionary.

• An order of hydroids.
• A suborder of Testudinata, contrasted with Athecæ, and containing all the tortoises whose carapace is perfect.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) A division of hydroids comprising those which have the hydranths in thecæ and the gonophores in capsules. The campanularians and sertularians are examples. Called also Thecata. See Illust. under hydroidea.