has component spicule triaxone 3 3 Architecture of the Skeleton and Spicules of Hexactinellida. WP: Triaxons have three axes; in triods, each axis bears a similar ray; in pentacts, the triaxon has five rays, four of which lie in a single plane; and pinnules are pentacts with large spines on the non-planar ray - Eugenio Andri; Stefania Gerbaudo; Massimiliano Testa (2001). Spicule with three axes. triaxon ray axis