Dictionary entry

Tetractinellida

Webster's Dictionary 1913

‖Te‐trac′ti‐nel″li‐da (?), n. pl. [NL., from Gr. τέτρα- tetra- + �, �, ray, spoke.] (Zoöl.) A division of Spongiæ in which the spicules are siliceous and have four branches diverging at right angles. Called also Tetractinellinæ.