Hexactinelline \Hex*ac`ti*nel"line\, a. [From NL. Hexactinellin[ae], fr. Gr. "e`x six + a dim. of ?, ?, a ray.] (Zool.) Belonging to the {Hexactinellin[ae]}, a group of sponges, having six-rayed siliceous spicules. [1913 Webster]