Anthoathecata

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 and heavily discussed group. It has also been called Gymnoblastea and (with or without an emended ending -ae), Anthomedusa, Athecata, Hydromedusa, and Stylasterina. There are about 1,200 species worldwide.

Capitata is a suborder of Hydrozoa, a class of marine invertebrates belonging to the phylum Cnidaria.

Filifera is a suborder of hydrozoans in the order Anthoathecata. They are found in marine, brackish and freshwater habitats.

Aplanulata is a suborder of Hydrozoa, a class of marine and freshwater invertebrates belonging to the phylum Cnidaria. The group have lost its planula larval stage, and the only remnants of the medusa stage is when they function as gonophores attached to the polyp.