40 W, Cross — Post- Laramie Deposits of Colorado. 



Lower Coryphodon beds, but Professor Cope says, in 1S83 : 

 " Coryphodon is, so far, unknown," and in his last synopsis of 

 the Puerco fauna (loc. cit.) he does not include that form. 



Regarding the first mammalia described by Prof. Marsh 

 "from the Laramie'' Prof. Cope* has said: "These species 

 are of identical character with the Puerco mammals, although 

 there is no species identical with any in the Puerco, where 

 there is not a single Cretaceous reptile. The mammals of the 

 Laramie are, like the saurians, rather Cretaceous than Tertiary ; 

 but the character is not as pronounced." 



The question as to the relations of the Laramie to the 

 Eoceue has recently been reviewed by Dr. C. A. White in the 

 Correlation Essay on the Cretaceous prepared for the Fifth 

 International Congress of Geologists, f and with the result 

 that the Laramie " is held to represent both the close of the 

 Cretaceous and the beginning of Tertiary time," with a proba- 

 bility that in certain known areas there has been continuous 

 sedimentation from the coal-bearing Laramie through to the 

 Wasatch Eocene or it equivalents. The molluscan fauna is 

 said to favor such a conclusion. 



Prof. J. S. Kewberry % has recently expressed the decided 

 opinion that the diverse views of geologists concerning the 

 Laramie have in large part " arisen from the fact that many 

 writers on the subject have combined two distinct formations 

 in the Laramie and have called them one, when they have 

 almost nothing common, belong to different geological systems, 

 and should never have been united." He then assigns the 

 Fort Union beds of Montana to the Eocene, and the remainder 

 of what has been called Laramie to the Cretaceous, asserting 

 that the floras of the two " are totally distinct." 



In discussing this paper Prof. L. F. Ward claimed that the 

 Ft. Union flora was not absolutely distinct from that of the 

 Laramie though very different, and that it might well be con- 

 sidered as Cretaceous. 



Prof. Marsh states§ that " the Ft. Union Eocene beds on the 

 Upper Missouri " rest immediately upon the " Ceratops beds." 

 It would be interesting to know the flora of the " Ceratops 

 beds" and the vertebrate fauna of the "Ft. Union beds" in 

 this region. Prof. Cope has published a " Description of some 

 vertebrate remains from the Ft. Union beds of Montana," | 



*Bull. Geol. Soc. of Am., vol. i, p. 532 (Dec. 1890). In discussion of a paper 

 by J. S. Newberry, The Laramie Group. 



f Correlation Papers. The Cretaceous, Bull. 82, TJ. S. Geological Survey, 1891. 

 Compare pp. 262. 



% The Laramie Group. Bull. Geol. Soc. of Am., vol. i. p. 524. 



§ This Journal, xlii. p. 336. 



|| Proc. Acad, of Nat. Sci. of Phila., vol. xxviii, p. 248, 1876. 



