Scientific Travellers. 291 



masses of marls, white and yellow limestones, and gray copper 

 grits, as the name of old red sandstone was found to be in re- 

 ference to the schistose black rocks of Devonshire. 



To this " Permian System" we refer the chief deposits of 

 gypsum of Arzamas, of Kazan, and of the rivers Piana, 

 Kama and Oufa, and of the environs of Orenbourg; we also 

 place in it the saline sources of Solikamsk and Sergiefsk, and 

 the rock salt of Iletsk and other localities in the government 

 of Orenbourg, as well as all the copper mines and the large 

 accumulations of plants and petrified wood, of which you have 

 given a list in the s Bulletin' of your Society (anno 1840). Of 

 the fossils of this system, some undescribed species of Producti 

 might seem to connect the Permian with the carboniferous 

 sera; and other shells, together with fishes and saurians, link 

 it on more closely to the period of the Zechstein, whilst its pe- 

 culiar plants appear to constitute a Flora of a type intermediate 

 between the epochs of the new red sandstone or " trias " and 

 the coal-measures. Hence it is that I have ventured to consi- 

 der this series as worthy of being regarded as a " System." 



The overlying red deposits which occupy a great basin in 

 the governments of Vologda and Nijni Novogorod, have not 

 as yet been found to contain any organic remains except minute 

 Cyprides and badly preserved Modioli ; but when we take into 

 consideration their thickness, geological position, and mineral 

 characters, we are disposed to think that they may at some fu- 

 ture day be identified with a portion of the " Trias" of German 

 geologists. I am strengthened in this opinion by Count Key- 

 serling's discovering, during our tour at Monte Bogdo, certain 

 fossils which are unknown in other parts of Russia, but which 

 are associated with the Ammonites Bogdoanus already described 

 by Von Buch, and which that distinguished geologist refers to 

 the type of the muschelkalk. 



True lias does not exist in Russia, as Von Buch had de- 

 cided from an examination of fossils sent to him, but the Ju- 

 rassic or oolitic series is divisible into two stages. The lowest 

 of these, which is much more developed than the upper, never 

 occupies any considerable tract of country, being either dis- 

 tributed in patches, or hidden by newer accumulations. From 

 the eastern flanks of the Ural chain in the 64° of N. latitude to 

 the Caspian Sea, it preserves nearly the same mineral and fos- 

 sil characters. This formation represents the inferior and mid- 

 dle oolite. The ferruginous sands, calcareous grits, and black 

 schists of the Moskwa are of this age ; and also those beds 

 which we examined last year on the Volga between Kostroma 

 and Kinshma, at Makarief upon the Unja, as well as those 

 shales and sands which we have seen this year in many other 



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