a. (Zool.) Having six-rayed spicules; belonging to the Hexactinellinæ. [ 1913 Webster ]
a. [ From NL. Hexactinellinæ, fr. Gr. "e`x six + a dim. of &unr_;, &unr_;, a ray.] (Zool.) Belonging to the Hexactinellinæ, a group of sponges, having six-rayed siliceous spicules. [1913 Webster]