Foraminiferida from outcrops of the Niobrara shale (Upper Cretaceous) of North Dakota

Microfossils were obtained from outcrop samples of the Niobrara Formation in northeastern North Dakota and from subsurface samples in southeastern North Dakota. Ninety-three species of foraminiferids, of which two are new and eight others of uncertain assignment, are described and figured. One species previously reported from the Oligocene and Niocene of Trinidad and two species from the Lower Oligocene and Niocene of Antigua, B. W. I., were collected and described which extend the range of those species down to the Upper Cretaceous. The major portion of the fauna described is correlative with previously described faunas from Nebraska, Kansas and South Dakota. The total fauna suggests that the age of the beds sampled in the Niobrara Formation extend from Coniacian to lower Campanian. Outcrops, in southern Barnes County, North Dakota, which were previously of unknown age and stratigraphic relations have been tentatively assigned to the Pierre Formation because of preservation and microfaunal similarity with foraminiferids of the known Pierre Formation in North Dakota