FLORA OF THE LARAMIE GROUP. 113 



the molloscan fauna would offer an incontestable evidence. Professor C. 

 A. White, in a paper lately published, 1 writes as follows: "The inverte- 

 brate fauna of the Laramie Group is wholly different from that of any of 

 the Marine Cretaceous formations, with one of which some writers have 

 confounded it. It contains no true marine type of any kind, but it does 

 contain many brackish-water molluscan forms, and also the remains of 

 many fresh and land mollusks. The fauna characterizes a great wide- 

 spread geological group of strata in the most distinct and unequivocal 

 manner, several of its molluscan species now being known to occur at 

 localities more than a thousand miles apart." After remarking on the 

 erroneous statements in the text-book of Geology by Professor Geikie, 

 and on the assertion of Professor J. P. Stevenson upon the presence of 

 marine strata of the Fox Hills Group alternating with those of the Lara- 

 mie, Professor White adds: "That any true Laramie strata ever alternate 

 with those of the Fox Hills Group, or any other Marine Cretaceous Group, 

 or that any true marine fossils were ever collected from any strata of the 

 Laramie Group, I cannot admit. I regard all such statements as the result 

 of a misunderstanding of the stratigraphical geology of a region in which 

 such observations are said to have been made." 



These remarks agree entirely with those I have had opportunity to 

 make in my researches on the flora of the Laramie Group. 2 The flora, 

 like the invertebrate fauna, is, on the whole, of a peculiar character, uni- 

 formly distributed over the whole extent of the formation, and free from 

 any types or characters relating it to the Cretaceous flora. As the Lara- 

 mie Group has never been subjected to submersion in the deep sea, the 

 few remains of Dinosaurians found in it are derived from low marine 

 lagoons penetrating into the land, and cannot impress the formation with 

 the Cretaceous character. This being the case, it is not at all surprising 

 to find remains of marine animals of Cretaceous types with remains of 

 plants of Tertiary age, not more than to find the bones of the marine 

 saurian Agatlmumas of Black Buttes enveloped in a mass of dicotyledon- 

 ous leaves, some of them even glued to the bones, and petrified with them 



1 Late observations concerning the Molluscan Fauna and the Geographical extent of the Laramie Group, 

 "Amer. Journ. of Sei.," 3d series, vol. xxv, p. 206 (1883). 



* " American Journal of Science, - ' 3d Ser., 1874, vol. xxv, pp. 546-557. 

 CF 8 



