UPPER PALEOZOIC FORMATIONS OF KANSAS 733 



Carboniferous are in general more nearly related to the Carbon- 

 iferous than the Zechstein, finds its explanation in the poverty 

 of the species of the inland seas. The Arta stage occupies a 

 large space on the western slope of the Ural mountains from the 

 Arctic ocean to the Kirghiz Steppe and the Donetz River, and 

 was correctly classified with the Dyas by older investigators 

 (Pander). The plant remains described by Schmalhausen speak 

 quite decidedly for a comparison with the western Rothliegende 1 

 Murchison considered the Arta sandstone the Millstone grit, 

 while the modern Russian authors mostly call it an intermediary 

 stage from the Carboniferous to the Dyas, Permo-Carboniferous. 

 If the latter assumption were correct, then the Cusel and Lebach 

 strata would also have to be regarded as transitional from the 

 Carboniferous to the Zechstein, i. e., the most important and 

 best known part of the formation would become a transition and 

 only the equivalent of the German Zechstein would be desig- 

 nated as Permian. 2 



Usage of Russian geologists. — Among the recent Russian geolo- 

 gists who have described transitional deposits between the Car- 

 boniferous and Permian systems, may be mentioned the follow- 

 ing: Krotow, who in 1888 described the Permo-Carboniferous 

 and Permian on the western slope of the Urals in the region of 

 Tscherdyn and Solikamsk. 3 Th. Tschernyschew, in 1889, 

 described the Permo-Carboniferous of the western slope of the 

 central Urals, which he lettered C P, and gave as composed of 

 the Artinsk (C Pg) , and superjacent Dolomitic limestone (C Pc) , 

 the latter forming the base of Murchison's Permian system. 4 

 Krasnopolsky, the same year, described the Permo-Carboniferous 

 and Permian deposits of another portion of the western Urals, 5 

 which was followed two years later by a further description. 6 

 Stuckenberg, in 1890, described the Permo-Carboniferous of 

 another region, which he gave as composed in ascending order 



1 Ibid., pp. 493, 494. 2 Ibid.,p. 493, f. 2. 



3 Mem. Comite Geologique, Vol. VI, pp. 553-9. 

 ''Ibid., Vol. Ill, No. 4, Blatt 139, pp. 356-66. 



5 Ibid., Vol. XI, No. 1, Blatt 126, pp. 506-18. 



6 Ibid., No. 2, 1 89 1, pp. 28-30. 



