Second Geological Survey of Russia in Europe. 65 



do so, not merely because a portion of the deposits in question lias 

 long been known by the name " grits of Perm," but because, being 

 enormously developed in the governments of Perm and Orenburg, 

 they there assume a great variety of lithological features, and con- 

 tain the bones of thecodont Saurians and certain fishes, also a more 

 copious fauna and flora than have ever been observed in their equi- 

 valents in Western Europe. 



The Permian rocks of Russia which occupy so vast a region to 

 the east of the river Volga, i.e. in the governments of Kasan, Viatka, 

 Perm and Orenburg, are composed of white limestone with gypsum, 

 red and green grits with shales and copper ores, magnesian lime- 

 stones, marl-stones, small conglomerates, red and green sandstones, 

 &c. By examining numerous natural sections between the neigh- 

 bourhood of Sviask, Kasan, and Samara, upon the west, and the 

 carboniferous limestone on the edge of the Ural mountains on the 

 east, the authors have come to the conclusion, that however the 

 lithological sequence may vary in different tracts, the whole of the 

 vast region alluded to is occupied by deposits which belong to one 

 class or zoological system of deposits. Thus, though the limestones 

 are sometimes white, sometimes yellow and pure magnesian, and 

 oftentimes pass into marl and marlstone, all of which can be observed 

 to inosculate with strata of red sandstone, conglomerate, &c, the 

 same fauna pervades the whole group. The Mollusca and Polypi- 

 fers are clearly of a type intermediate between those of the carboni- 

 ferous limestone and those of the Trias or new red sandstone group 

 of Continental geologists. Among the most characteristic of these 

 fossils may be enumerated Productus horrescens, n.s., P. Cancrini, 

 n.s., Spirifer lamellosus (L'Ev.), Terebratula elongata (Schloth.), T. 

 Roysii (L'Ev.) (T. Roysii, L'Ev. = Atrypa pectinifera, Sow. Min. 

 Conch. No. 107), Natica variata (Phil.), Modiola Pallasii, n.s., 

 Gervillia lunulata (Phil.), Ostrcea matercula, n.s., Corbula Rossica, 

 n.s., Avicula Kasaniensis, n.s., A. antiqua (Schloth.), A. cheratophaga 

 (Schloth.), Lingula parallela (Phil.), Limulus oculatus (Kutorga), 

 Cytherina ; with Reteporajlustracea, Gorgonia,Millepora, &c. &c. 



In the conglomerates and sandstones, fishes have been found, 

 some of which belong to the genus Palseoniscus, so characteristic 

 of the Zechstein and magnesian limestones ; and the Saurian bones, 

 portions of which have been figured by M. Kutorga, and more per- 

 fect remains of which have been described by Professor Fischer von 



view has been communicated in my anniversary discourse, respecting the 

 first use of the word ' Zechstein ' in reference to the deposits of Perm, that 

 term having been used, as he assures me, by German viiners, who visited 

 Russia long ago, though no proofs have been since offered to sustain its ap- 

 plication in a geological sense. I also take this opportunity to state, that 

 through a misapprehension of his views, derived from a perusal of the Bul- 

 letin de la Societe" Geologique de France, I have been led into a mistake in 

 supposing that M. Erman believed a large portion of the Russian rocks, 

 now shown to be carboniferous, to belong to the Jurassic epoch. I willingly 

 adopt this correction of my views in reference to the distinguished modern 

 explorer of Siberia and Kamschatka." — R. I. M., Sept. 1842. 



Phil. Mag. S. 3. Vol. 23. No. 149. My 1843. F 



