Staurocladia is a genus of anthomedusan hydrozoans. Cladonematidae is a small family of anthomedusan hydrozoans. Staurozoa is a class of Medusozoa, jellyfishes and hydrozoans. Limnomedusae is an order of hydrozoans. Plumulariidae is a family of hydrozoans. Stylasteridae is a family of hydrozoans. Cnidarians include corals, sea anemones, jellyfish and hydrozoans. Crossota is a genus of hydrozoans of the family Rhopalonematidae. Narcomedusae is an order of hydrozoans in the subclass Trachylinae. Hydroidolina is a subclass of hydrozoans in the phylum Cnidaria. Turritopsis is a genus of hydrozoans in the family Oceaniidae. Benthocodon is a monotypic genus of hydrozoans of the family Rhopalonematidae. Ectopleura is a genus of hydrozoans in the family Tubulariidae. Pandea is a genus of hydrozoans of the family Pandeidae. Clava is a monotypic genus of hydrozoans in the family Hydractiniidae.