phylum, encompassing corals, sea anemones, jelly fish, colonial hydroids, and ctenophores (comb jellies). It is more common to split the corals, sea anemones, jelly fish, and colonial hydroids into the phylum Cnidaria. Cratinaster: Cratinaster mccarteri is the famous starfish species on the large Cretaceous slab currently on display at TMM. You may know it better as Austinaster mccarteri Adkins; unfortunately, this species had already been described and assigned a name before Adkins named his specimen, and so this 'local' name is incorrect! ( Starfish and sea urchins)
Coelenterata is an obsolete yet common term encompassing two animal phyla, the Ctenophora (comb jellies) and the Cnidaria (coral animals, true jellies, sea anemones, sea pens, and their allies). The taxon name comes from the Greek "koilos" ("hollow"), referring to the hollow body cavity common to these two phyla. They have very simple tissue organisation, with only two layers of cells, external and internal.