Opisthobranch Mollusks from the Southern Tropical Pacific

Twenty-four species of opisthobranchs are listed from the southern tropical Pacific Ocean, from Fiji and the Ellice Islands eastward to the Tuamotus. Two new genera are described: Pleurebdera (Pleurobranchidae; type species: P. haraldi n. sp., Tuamotus) and Pupsikus (Dorididae; type species: P. pinguis n. sp., Tahiti). The following five other new species and subspecies are described and figured : Noumea norba (Dorididae: Chromodoridinae, Viti Levu, Fiji); Peronodoris rebderi (Dorididae: Archidoridinae, Tahiti); Tayuva ketos juva (Dorididae: Discodoridinae, Rurutu , Tubuai Islands ); Phyllidia tula (Phyllidiidae, Nukulaelae, Ellice Islands); Phyllidia soria (Tahiti) . The internal anatomy of these species, as well as of many of the previously known species, is described. Many species are recorded from Polynesia for the first time.