Class: Hydrozoa Owen, 1843
Subclass Hydroidolina Collins & Marques, 2004
   Order: Thecata (Leptomedusae) Fleming, 1828
       Suborder: Conica Broch, 1910
- Family:Campanulinidae Hinks, 1868
- Family:Haleciidae Hincks, 1868
- Family:Lafoeidae Hincks, 1868
- Family:Phialellidae Russell, 1953
- Family:Sertulariidae, 1812
- Abietinaria pulchra (Nutting, 1904)
- Sertularella polyzonians (Linnaeus, 1758)
- Sertularella rugosa (Linnaeus, 1758)
- Sertularella tenella (Alder, 1856)
- Sertularia cf. albimaris (Mereschowsky, 1878)
- Sertularia argentea (Linneaeus, 1758)
- Sertularia cupressoides (Clark, 1876)
- Sertularia fabricii (Levinsen, 1893)
- Sertularia mirabilis (Verrill, 1873)
- Sertularia schmidti (Kudelin, 1914)
- Sertularia cf. similis (Clark, 1877)
- Symplectoscyphus tricuspidatus (Alder, 1856)
- Tamarisca tamarisca (Linnaeus, 1758)
- Thuiaria articulata (Pallas, 1766)
- Thuiaria laxa (Allman, 1874)
- Family:Tiarannidae Russel, 1940
       Suborder: Proboscoida Broch, 1910
   Order: Athecata (Anthomedusae) Hincks, 1686