Notes on Some Opisthobranchia (Mollusca: Gastropoda) from the Marshall Islands, Including 57 New Records

The rich opisthobranch fauna of the Marshall Islands has remained largely unstudied because of the geographic remoteness of these Pacific islands. We report on a long-term collection of Opisthobranchia assembled from the atolls of Bikini, Enewetak, Kwajalein, Rongelap, and Ujelang . Fifty-seven new records for the Marshall Islands are recorded, raising to 103 the number of species reported from these islands. Aspects of the morphology, ecology, development, and systematics of 76 of these species are discussed.