a. Zool. [f. TETRA- + Gr. κλάδ-ος shoot, sprout.] Branching in four; having four arms or rays. So Tetracladine a., of or pertaining to the Tetraclādina, a suborder of lithistid sponges having spicules branching into four or more processes; also Tetracladose a. in same sense.
1881. P. M. Duncan, in Jrnl. Linn. Soc., XV. No. 86. 324. The quadrifid or tetraclade spicula.
1887. Sollas, in Encycl. Brit., XXII. 417/1. (Sponges) Some or all of the rays of the primitive calthrops … may bifurcate once or twice and finally terminate by subdividing into numerous variously shaped processes; such a tetracladine desma characterizes one division of the Lithistid sponges. Ibid., 422/1. A distinct passage can be traced from the Tetracladose to the Rhabdocrepid group. Ibid. The scleroblast … in the Tetracladine Lithistids lies in an angle between the arms.
