XXXVIII 



INTRODUCTORY REMARKS, 



In the Upper division, Dr. Newberry found no recognizable animal 

 remains excepting in a thin bed at its base, and therefore thought that por- 

 tions of this division above the base, may possibly be Tertiary He found no 

 fossils (either old or new species) crossing the line between Ids Middle and 

 Upper divisions, which line corresponds to that separating our Niobrara and 

 Fort Pierre groups. In the same way, Dr. Shumard found in Texas the 

 species distinct above and below this line. (See Trans. St. Louis Acad., 

 I, 583.) 



After the foregoing rather cursory outline-sketch of the geographical dis- 

 tribution of the rocks under consideration in the great area of country west 

 of the Mississippi, and chiefly east of the Rocky Mountains, their relations to 

 the Cretaceous deposits farther eastward in this country and in Europe 

 remain to lie considered. 



RELATIONS OF THE UPPER MISSOURI CRETACEOUS BEDS TO THOSE IN THIS 

 COUNTRY EAST OF THE MISSISSIPPI. 



Coming eastward to the State of Mississippi, we find the Cretaceous 

 rocks of that State, according to Professor Hilgard, separable into four sub- 

 ordinate groups as follows, numbering from below. 



Section of the Cretaceous rod's of Mississippi, from Professor HilguriVs report. 



