148 Scientific InieWgence. 



United States boundary, called Tertiary by G. M. Dawson, seven 

 are identical with, and five related to, species of the Lower Mio- 

 cene of Europe, two occur in the Arctic Miocene, three are found 

 also at Golden, eight at Black Butte, and two have some analogy 

 with Cretaceous types. 



Hayden, in his* remarks on the Lignitic beds, observes that 

 there are lignitic or coal beds in both the Cretaceous and Ter- 

 tiary formations of the Rocky Mountain region; but that, so far 

 as Eastern Colorado is concerned, from Raton Hills to Cheyenne, 

 the lignitic beds are not associated with marine deposits, but 

 those of brackish water or freshwater origin, and that these are 

 not Cretaceous, but of Eocene age, the evidence from the plants 

 pointing, according to Lesquereux, to this conclusion. He further 

 states that in Southern and Southwestern Colorado, as shown by 

 Mr. Holmes and Dr. Endlich of the expedition, and also other 

 authorities, heavy beds of coal occur all through the Cretaceous. 

 Hence, taking, he says, the whole Rocky Mountain region into 

 view-, there is a Lower Lignitic group which is marine and Cre- 

 taceous ; above this, the Middle Lignitic, brackish water in origin, 

 which is Lower Tertiary or transitional ; and next the Upper 

 Lignitic^ freshwater in origin, which is unquestionably Tertiarg. 

 The coal deposits of Carbon are included in the third of these 

 divisions, and those of Bear River and Cordville in the first. Dr. 

 Hayden observes that Dinosaurian remains occur even in the 

 freshwater or upper division, as noticed by Cope and Marsh ; but 

 that the species are not identical with any known Cretaceous 

 species. The Green River beds overlie the Lignitic beds uncon- 

 formably. 



The difference between Prof. Lesquereux's view and those of 

 Dr. Hayden appears to be this : Lesquereiix makes the Eocene to 

 include the Bear River and Coalville beds, and all the older Lig- 

 netic beds the fossil plants of which he has examined (including 

 those even of Vancouver Island, where Ammonites and Baculites 

 occur in beds overlying the coal) ; while Dr. Hayden admits that 

 there is a series of Cretaceous coal beds, that the Bear River and 

 Coalville deposits are included in it, and that these Cretaceous 

 strata are distinguished by being mainly marine and containing 

 Cretaceous fossils. 



Between the views of Prof. Lesquereux and those of the 

 zoological paleontologists the divergence is great. For while 

 he makes the Green River beds (containing remains of fossil 

 plants and fishes) " Upper Miocene," and the Carbon beds " Mid- 

 dle Miocene," Leidy, Cope, and Marsh hold that even higher 

 strata, namely, those overlying the Green River beds conformably 

 (having an estimated thickness of five or six thousand feet) and 

 which contain the oldest Mammalian remains of that part of the 

 continent, are Eocene ; and that the underlying Green River beds 

 are Lower Eocene ; and further that all the Liginitic beds, that 

 are older than the Green River beds, are Cretaceous, since they 

 contain Dinosaurian remains,' and some of them other Cretaceous 



