The Urticina crassicornis is called the Painted Anemone or the Christmas Anemone, as it's often red and green. What a beautiful anemone!
The lovely Short Plumose Anemone is smaller than the giant version. Here on Indian Island, I find mostly white ones, with some brown ones. They close up tight at low tide.
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria. They are named for the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. Anthozoa often have large polyps that allow for digestion of larger prey and also lack a medusa stage. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra.