Thecate Hydroids (Leptothecatae) also commonly known as Hydromedusae, is a biological order of the phylum Cnidaria (Cnidarians) and class Hydrozoa (Hydralike Animals).
Aequoreidae
Aglaopheniidae
Blackfordiidae
Bonneviellidae
Calycellidae
Campanulariidae
Campanulinidae
Cirrholoveniidae
Dipleurosomatidae
Eirenidae
Eucheilotidae
Haleciidae
Halopterididae
Kirchenpaueriidae
Lafoeidae
Laodiceidae
Lovenellidae
Malagazziidae
Melicertidae
Mitrocomidae
Octocannoidae
Orchistomatidae
Phialellidae
Phialuciidae
Plumulariidae
Sertulariidae
Syntheciidae
Thyroscyphidae
Tiarannidae
Tiaropsidae
Actinulida
Anthoathecatae
Limnomedusae
Narcomedusae
Siphonophorae
Leptothecatae
Trachymedusae