RADIATA, a term introduced by Cuvier in 1812 to denote the lowest of his four great animal groups or "embranchements."
Vertebres) also used the term, as when he spoke of the Medusae as radiata medusaria et anomala; but he preferred the term Radiaria, under which he included Echinodermata and Medusae.
In 18J5, however, Owen included under Lamarck's term Radiaria the Echinodermata, Anthozoa, Acalepha and Hydrozoa, while Agassiz also clung to the term Radiata as including Echinodermata, Acalepha and Polypi, regarding their separation into Coelenterata and Echinodermata as "an exaggeration of their anatomical differences" (Essay on Classification, London, 1859).
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