ZOOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site radiolarian Any protozoan of the class Polycystinea (superclass Actinopoda). Radiolaria are found as zooplankton in the upper layers of all oceans. They are mostly spherically symmetrical and known for their tiny, complex, perforated skeletons, known as tests, which are usually composed of silica. Related category    • ZOOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP