MALACOLOGIA, 1965, 3(2): 263-286 SOME OPISTHOBRANCHIA FROM MICRONESIA Ernst Marcus Faculdade de Filosofía, Ciencias e Letras Universidade de Sao Paulo sao Paulo, Brasil ABSTRACT A Micronesian collection of 130 opisthobranchs belonging to the U. S. National Museum contained 53 species. Only 10 of them are new, and half of these are less than 5 mm in length. These small numbers show the uniformity of the opisthobranch fauna on the reefs in the Indo-West Pacific Ocean, most of whose bigger species are already known. The following new species are described: Stiliger {Ercolania) illus, Elysia bayeri, Elysia ratna, Hypselodoris cuis, Dis-codoris lora, Discodoris ylva, Catriona lonca, Catriona urqväsa, Noumeaella rehderi, and Muessa evelinae, the type-species of a new genus of the Favorini-dae, allied to Herviella. Some time ago, Dr. Harald A. Rehder of the Smithsonian Institution, Washing-ton, D.C., U.S.A., sent me for identifi-cation a collection of 130 lots of opis-thobranch mollusks from Micronesia. All of this material was collected in recent years by biologists and geolo-gists sent out on surveys of islands in several of the groups making up this region of the central western Pacific. Of the 53 species identified in this sending, 10 are new, 5 of them being less than 5 mm in length. The recog-nized uniformity of the Indo-West Pacific reef fauna, and the relatively advanced state of exploration account for the small percentage (18.9) of new species. In our first collection from the little known coast of Brazil, 71.8% were new species. My thanks are due to Dr. Harald A. Rehder for having gone over the manu-script, and to Dr. F. M. Bayer, of the Marine Institute in Miami, Florida, for having furnished many of the color notes used in the description ofthe new species. SYSTEMATICS AND DISTRIBUTION A systematic list of species of Euthy-neura collected in Micronesia during the field study are listed below. The species are treated individually in consecutive order in the section following the list. Soleolifera, Onchidiacea, Onchidiidae 1. Peronia {Peronia) peronii (Cuv-ier) Cephalaspidea, Bullacea, Retusidae 2. Retusa sp. Cephalaspidea, Philinacea, Phanero-phthalmidae 3. Phanerophthalmus luteus (Quoy and Gaimard) Cephalaspidea, Philinacea, Aglajidae 4. Aglaja splendida Risbec 5. Chelidonura inornata Baba 6. Chelidonura hirundinina elegans Bergh Anaspidea, Aplysiidae, Aplysiinae 7. Aplysia (Varria) dactylomela Rang 8. Aplysia {Varria) pulmonica Gould 9. Aplysia (Pruvotaplysia) párvula Mörch Anaspidea, Aplysiidae, Dolabellinae 10. Dolabella auricularia (Solander) Anaspidea, Aplysiidae, Dolabriferinae 11. Dolabrifera dolabrifera (Rang) ^Published with the cooperation of the Institute of Malacology. (263)
BioStor
