Anthoathecata, or the athecate hydroids, are an order of hydrozoans belonging to the phylum Cnidaria. A profusion of alternate scientific names exists for this long-known, heavily discussed, and spectacular group. It has also been called Gymnoblastea and, Anthomedusa, Athecata, Hydromedusa, and Stylasterina. There are about 1,200 species worldwide.
