What animals are in the animal phylum cnidarians?

The cnidarian groups are broken down first into two large groups; one contains the jellyfish (Medusozoa), and the other contains the corals and anemones (Anthozoa).

Within the Medusozoa, there are four basic groups; Cubozoa(box jellies), Hydrozoa(Hyras), Scyphozoa(regular jellyfish) and Staurozoa(stalked Jellyfish).

The orgainization of the Anthozoa is more complex, but basically they are the Hexacorallia and the Octocorallia. The Hexacorallia group consists of sea anemones, hard corals, black corals, 'mushroom corals', and the colonial zooanthids. The octocorralia consists of the 8 tentacled soft corals, and sea pens.