tetractinellida

from The Century Dictionary.

• In Sollas's classification of sponges, the second tribe of Silicispongiæ, contrasted with Monaxonida, including those Demospongiæ which possess quadriradiate or triæne spicules or lithistid scleres.

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

• noun plural (Zoöl.) A division of Spongiæ in which the spicules are siliceous and have four branches diverging at right angles. Called also Tetractinellinæ.