NEW SPECIES OF NERITID GASTROPODS FROM CRETACEOUS AND LOWER CENOZOIC STRATA OF THE PACIFIC SLOPE OF NORTH-AMERICA

Ten new species of neritid gastropods are described from the fossil re cord of the Pacific slope of North America. Nerita (Amphinerita) sos s p. nov., from northern California, is of Early Cretaceous (Hauterivian ) age and is the earliest record of Amphinerita. Nerita (Amphinerita) vacca sp. nov., from northern California, is of Late Cretaceous (Turon ian) age. Nerita (Bajanerita?) larix sp. nov., from Washington, is of middle early Eocene (''Capay'') age. Nerita (subgenus?) salsa sp. nov. , from northern California, is of Turonian age. Otostoma lucanus sp. n ov., from southern California, is of Turonian age, and Otostoma? atopo s sp. nov., from northern California, is of late Early Cretaceous (Alb ian) age. Corsania (Corsania) allisoni sp. nov., from Baja California, Mexico, is of Albian age. Corsania (Januncia) rhoga sp. nov., from no rthern California, is of early Paleocene age, and Corsania (J.) susana sp. nov., from southern California, is of late Paleocene age. Corsani a (J) oraria sp. nov., a Washington species of middle early Eocene age , is the youngest record of this genus and subgenus and the first reco rd of them in the Eocene of the Pacific coast of North America. Althou gh neritids are of sufficiently uncommon occurrence north of Baja Cali fornia to make them of limited biostratigraphic importance, their ther mophilic tendencies make them useful in recognizing periods of warmer climate.