THE TAXONOMIC STATUS OF THE GENUS STYLACTARIA STECHOW, 1921 (HYDROIDOMEDUSAE, ANTHOMEDUSAE, HYDRACTINIIDAE), WITH THE DESCRIPTION OF A NEW SPECIES

The status of all the species ascribed in the literature to Stylactari a is discussed, that nominal genus is considered a congener of Hydract inia and a new species (Hydractinia calderi n. sp.) is described. The medusae of the medusa-based genera Hansiella and Tregoubovia, formerly ascribed to the Hydractiniidae, are shown to be more like the medusae of Thecocodium, a genus having ptilocodiid hydroids. Both Hansiella a nd Tregoubovia are thus transferred to the Ptilocodiidae. With their r emoval from the Hydractiniidae, a redefinition of both families is pro vided. The genus Fiordlandia is considered as synonym of Clavactinia.