[Acantharia]Term applied to acantharians in which all pairs of opposing radial [l][m]Glossary[/m][r]Spicule[/r]spicules are fused, or simply unseparated, at their basal ends; the 10 diametral spicules cross loosely in the center of the shell. When opposing spicules are not fused in pairs but form a central star-shaped or spherical concretion, or join otherwise in the center, the term radial spicule (Phyllostauridae) is used. (Acanthochiasma fusiforme ;
Acanthochiasma planum ).