RADIOLARIAN

[ra.di.o.lar.i.an] n [ultim. fr. LL radiolus small sunbeam, fr. dim. of L radius ray--more at ray] (1877): any of three classes (Acantharia, Polycystina, and Phaeodaria) of usu. spherical marine protozoans having radiating threadlike pseudopodia and often a siliceous skeleton of spicules -- radiolarian adj