A scanning electron microscopic view of the shell of a nassellarian, polycystine radiolarian. The shells of nassellarian radiolaria are commonly conical or elongate and segmented. Some species, however, consist only of a tripodal arranged set of spines. The central capsule is enclosed within the very small segment at the top of the shell.
A light microscopic view of a living nassellarian radiolarian (Eucyrtidium acuminata) showing the reddish pigmented cytoplasm within the siliceous, conical shell.
