Marine protozoa

Wiktionary Word definitions in Wiktionary
n. The members of the taxonomic subclass Radiolaria; radiolarians.

Wikipedia Word definitions in Wikipedia
The Radiolaria , also called Radiozoa , are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons , typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm . They are found as zooplankton ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Radiolaria \Ra`di*o*la"ri*a\ (r[=a]`d[i^]*[-o]*l[=a]"r[i^]*[.a]), n. pl. [NL. See Radioli .] (Zo["o]l.) Order of rhizopods, usually having a siliceous skeleton, or shell, and sometimes radiating spicules. The pseudopodia project from the body like rays. ...