548 AC. VEATIOE 
In connection with this suggestion of expediency, it should be 
pointed out that the continued use of this term in the “catchall” 
sense is wholly at variance with the abundance of strong and wholly 
logical reasons for the restriction of the term ‘‘Laramie”’ to the 
“Upper Laramie” shown by the historical considerations already 
presented. If the point of confusion is regarded as one of great 
importance, it might be worth while considering the entire abandon- 
ment of the term ‘“‘ Laramie.” 
In either case a new name is required for the beds here referred 
to as Lower Laramie. Many considerations suggest that this name 
should come from the region of the Laramie Plains. ‘This would be 
historically appropriate in many ways, and would result in placing 
the type locality of both the upper and the lower portions of the 
beds which have been called Laramie in the broad sense, in the same 
section. There are reasons for believing that the enormous develop- 
ment of Lower Laramie beds in the western part of the Laramie 
Plains near the mouth of the Medicine Bow River, or, as it is more 
commonly called by the local people, ‘‘The Bow,” where there is 
relatively very little evidence of a break between the upper and lower 
beds, more completely represents the Laramie deposition than at any 
other point now known. These considerations make the ‘Bow forma- 
tion” or ‘‘group’’ a very appropriate designation for these lower beds. 
On the other hand, the fact that the region of Golden has been made 
classic in connection with the ‘Laramie problem” by the studies of 
Cross, Eldridge, Knowlton, and others, raises the question whether 
‘the name “Golden formation” or “group” might not be a more 
appropriate name. ; 
The discovery of this great unconformity at all points that have 
been critically examined over an area 1,000 miles north and south 
and 250 miles east and west, the fact that it occurs on both the east 
and west sides of the Front Range of the Rocky Mountains, and its 
great magnitude, all make it one of the important mile-posts in the 
geologic history of western North America. All these considerations 
suggest anew the first conclusion of Cross in the Denver region that 
this unconformity marks the dividing line between the Cretaceous 
and Eocene in this region. On this basis the arrangement of groups 
immediately above and below the great break would be as follows: 
