146 CHARLES S. PROSSER 



studied the fossils of these deposits who find the differences between 

 the Kansan Pennsylvanian and Permian life greater and more marked 

 than I have ever claimed. As to the second opinion I have attempted 

 to consider all evidence concerning the age of these formations, 

 whether it agreed with the results of my studies or not, and to give it 

 due weight in forming my opinion regarding the correlation of these 

 deposits. 



Concerning the correlation of the Kansas deposits with the Russian 

 Permian it is interesting to note that Murchison — the author of the 

 Permian system — accepted it. He wrote as follows: 



Only of late years have we obtained information of the Permian species of 

 America. It is interesting to find there that the same genera characterize the 

 last of the Palaeozoic systems as in Europe. In Kansas, Texas, and Nebraska, 

 Permian rocks occur containing Productus, Camarophoria, Strophalosia, Strep- 

 torhynchus, Chonetes, Spirifer, Edmondia, Gervillia, Monotis, Schizodus, Mur- 

 chisonia, Orthoceras, Bellerophon, and Fenestella. Not only are the genera 

 the same there as in the eastern hemisphere, but in several cases the species are 

 identical with those found in the Magnesian Limestone and Zechstein. These 

 fossils have been described by Messrs. Meek and Hayden, Swallow and Hawn, 

 Shumard, and very recently by Geinitz." 



Since the writer's last reviews of the literature regarding the 

 correlation of the Upper Paleozoic of Kansas and related regions^ 

 several papers have been published which are of importance in this 

 discussion. In this last review, however, I seem to have overlooked 

 Dr. C. R. Eastman's paper on the " Carboniferous Fishes from the 

 Central Western States" in which he reviewed briefly the correlation 

 of the Upper Paleozoic formations of the Kansas-Nebraskan area 

 and wrote as follows : 



But in the upper terrane, the so-called "Red Beds" or Cimarron series, which 

 exhibit a thickness further southward of from 1,000 to perhaps 2,200 feet, no 

 fossils have been found which are at all closely related to those of the Coal 

 Measures, and writers are pretty generally agreed in correlating this series with 

 the Upper Permian (Neo-Dyas) of Europe. 



In the same way there appears to be good reason for believing that the lower 

 part of the Big Blue series (Chase and Neosho strata) correspond to the Artinsk 

 stage, which is the oldest Permian of Russia.^ 



^ Siluria, 5th ed., 1872, pp. 341, 342. 



2 Jour. Geol., Vol. X, 1902, pp. 721-37; Amer. Geologist, Vol. XXXVI, 1905, pp. 

 142-62. 



3 Bull. Mus. Comp. Zoology Harvard College, Vol. XXXIX, 1903, p. 165. 



