TF. Cross — Post-Laramie Deposits of Colorado. 41 



but without any statement of locality or stratigraphical data, 

 so that his paper stands rather as an illustration of the common 

 manner in which uncertainty and confusion have been intro- 

 duced into the literature of the Laramie, rather than as evi- 

 dence that Dinosaurs occur in beds containing the Ft. Union 

 flora. 



From these recent expressions of opinion concerning the 

 Laramie in its comprehensive sense and of the period of time 

 between the marine Cretaceous and the Puerco or lower 

 Eocene, it is clear that paleontologists have sought to correlate 

 the formation and characterize the period from the evidence 

 of the flora or of a particular fauna. In some cases at least 

 the opinion has been rendered upon biological grounds alone, 

 and has been announced with great confidence, often with but 

 the slightest reference to the results reached upon other pale- 

 ontological evidence or to contrary opinions from the same 

 evidence, with little regard for known facts of stratigraphy, 

 and still less for the very important fact of utter ignorance 

 concerning the actual relationships of some of the places, hori- 

 zons, and faunas or floras dogmatically correlated. This vari- 

 ance of opinion is a natural result of the methods used, yet no 

 one will dissent from the proposition that a correct knowledge 

 of the history of this interesting period cannot be reached 

 until all classes of evidence are carefully compared on a basis 

 of unbiased and accurate observations in all directions. 



The facts brought together in this paper point to one impor- 

 tant epoch in the period under discussion which has not been 

 duly recognized, to say the least. Its broad intrinsic impor- 

 tance has yet to be determined, and the writer wishes to dis- 

 tinctly express his appreciation of the fact that that importance 

 must ultimately be measured in great degree through the effect 

 exercised by the conditions of that epoch upon the life of the 

 time. But the great importance of the orographic movement 

 which has been identified, in relation to the physical history of 

 a very large district, must also be borne in mind. 



In conclusion, the writer wishes to advocate the restriction 

 of the term Laramie, in accordance with its original definition, 

 to the series of conformable beds succeeding the marine Mon- 

 tana Cretaceous, and the grouping of the post-Laramie lake- 

 beds described, with their demonstrated equivalents, in another 

 series to which a comprehensive name shall eventually be 

 given. This course has already been proposed by Mr. Hills in 

 his conclusion which has been cited (p. 33). The question as 

 to whether the series shall be referred to the Cretaceous or to 

 the Eocene cannot be finally settled until the various conflict- 

 ing elements of the evidence have been adjusted on a basis of 



