1) Cnidaria 2) Phylum 3) Phylum cnidaria 4) Phylum coelenterata 1) Cnidaria 
== Characteristics == All coelenterates are aquatic, mostly marine. The bodyform is radially symmetrical with a tissue grade of organisation. The body has a single opening hypostome surrounded by sensory tentacles leading into a spacious cavity called the gastrovascular cavity or coelenteron. Digestion is both intracellular and extracellular. Resp...
• (n. pl.) A comprehensive group of Invertebrata, mostly marine, comprising the Anthozoa, Hydrozoa, and Ctenophora. The name implies that the stomach and body cavities are one. The group is sometimes enlarged so as to include the sponges.
One of the major phyla of invertebrates, to which such forms as jellyfish belong. ... (05 Mar 2000) ... 
(se-len″tәr-a´tә) former name for a phylum of marine invertebrates now assigned to the phylum Cnidaria.
Type: Term Pronunciation: sē-len′tĕ-rā′tă Definitions: 1. One of the major phyla of invertebrates, to which such forms as jellyfish belong.
the phylum comprising the coelenterates. Cf. Cnidaria.