INTRODUCTORY REMARKS. 



XXXVII 



under the brackish-water deposits at the mouth of Judith River) being well 

 defined west of Greeley in Colorado, at which locality their true relations to 

 this group were firs! determined. 



The Fox Hills heds also occur at the base of the Rocky Mountains 

 near Pike's Peak, and probably at other localities in Colorado. It seems, 

 however, not to have been developed as a distinct rock anywhere on the 

 Missouri below the Fox Hills anil Moreau River regions, nor have any of 

 its fossils been brought from Eastern Nebraska, Kansas, the Indian Territory, 

 or Arkansas. 



Allusion has already been made several times to the occurrence of the 

 Upper Missouri Cretaceous subdivisions in New Mexico. This will be more 

 clearly illustrated by the following tabular section of the three groups into 

 which Dr. Newberry divides the Cretaceous series there, with a column 

 added on the right showing the Upper Missouri equivalents. The well- 

 known species of fossils found by him there in each subdivision are also 

 inserted in the section.* 



New Mexican Cretaceous series, showing the divisions recognized there by Dr. J. S. Newberry, 

 with Upper Missouri equivalents added here. 



*See Dr. Newberry's report on the geology of the expedition from Santja IV to the junction of the 

 Grand and Green Rivers, under the command of Captain Macomb, of the United States Topographical 

 Engineers, and a report by tie writer on the Cretaceous fossils collected by Captain Macomb's expedi- 

 tion; both now issuing from the press. 



