Radiata

Radiata, one of the four embranchemens into which Cuvier (1812) divided the animal kingdom, the other three being Articulata, Mollusca, and Vertebrata. In the division Radiata Cuvier recognised five classes—viz. (1) the Echinodermata, (2) the Entozoa (or Intestinal Worms), (3) the Acalephæ (or Jelly-fish), (4) the Polypi (Hydroids and Polyzoa), and (5) the Infusoria (Rotifers and Protozoa). It is hardly necessary to say that this exceedingly heterogeneous assemblage, or 'radiate mob,' as Huxley termed it, is now broken up into numerous distinct classes.