Actiniaria

Actiniaria, the order of Anthozoa, which includes the sea anemones. Actinia, which has been described, is a fairly typical representative of the group. The principal variations are that some are not attached, but free-swimming, as Minyas, or burrowing in mud, as Peachia; in some the mesenteries are eight (Edwardsia) or in multiples of eight (Paractiniae), though they usually conform to the hexameral (six-rayed) arrangement of the Anthozoa.