WAcryptolaria
WAequorea
WAglaophenia
WAglaopheniidae
WCampanularia
WCampanulariidae
WClytia (hydrozoan)
WConica (suborder)
WCorhiza
WCryptolaria
WCuvieria (hydrozoan)
WEirenidae
WEutonina
WGattya
WHalecium
WHalopterididae
WKirchenpaueriidae
WLeptothecata
WMacrorhynchia
WOrchistoma
WPhialella
WPhialella zappai
WPlanar hydroid
WPlumularia
WPlumularia setacea
WPlumulariidae
WPlumularioidea
WPycnotheca
WRhacostoma
WScandia mutabilis
WSertularella gayi
WSertularella polyzonias
WSertularia
WSertulariidae
WStaurotheca
WThuiaria
WTima (hydrozoan)
WTima formosa
WZygophylax pinnata