Trissocyclid Radiolaria from 54 samples of Eocene to Quaternary age, including deep sea cores from the Pacific and outcrops in the Antilles, are described and illustrated. The family Trissocyclidae is raised from subfamily rank and emended to include members of the suborder Nassellarina that have sagittal rings. Skeletal morphology is described. Seven evolutionary lineages are arranged in five emended genera. The genera Dendrospyris and Liriospyris are emended and 9 (5 new) and 10 (6 new) species, respectively, described herein.