30 The Hon. Mr. Strangways on the Geology of Russia. 



Opposite to Cazan, near the town of Iviashsk, commences a high ridge of 

 hills, which run due south between the Volga and Sviaga as far as Simbirsk. 

 Thence it skirts the whole right bank of the Volga to near Sarepta, and forms the 

 eastern part of the High Steppe of Pallas. The northern part is still wooded ; 

 but the remainder is more like the downs of the south and west of England 

 than anything I have seen on the continent. The greatest part of what Pal- 

 las described in 1769 as open Steppe, is now brought into cultivation, some of 

 the hills being left for cattle as in this country. 



In the Ouslonsky hills, that part of the chain immediately opposite Cazan, 

 the cliffs on the right bank of the Volga show the usual alternations of red 

 and white marl. There are also some beds of a Hmestone whiter than that of 

 Cazan, and somewhat more like the white limestone of the interior ; which is 

 likewise quarried and brought to Cazan. It may be of the same kind with 

 the white magnesian limestone of Roche Abbey near Doncaster. 



I will mention here another deposit apparently not connected with the salt 

 formation, but which appears in several patches along the central part of Rus- 

 sia. It is a black clay, containing pyrites and green sand in abundance, and 

 usually full of organic remains. Its most eastern locality that I have seen, is 

 at Simbirsk *, where it occurs at the foot of the hill under the town, on 

 the bank of the Volga ; it is probably continued on the other bank ; and it 

 appears also at Polymnia, a few versts higher up the river. It is well seen 

 below the church nearest to the river, where large slabs containing ammonites 

 of great size, beautifully iridescent, are lying at the surface of the ground. 

 There are also seen in it mytilites, and a few large and coarse septaria. The 

 apparent situation of this rock is under the sand. 



A similar rock is found also at Mourzikha on the Soura near Courmish, 

 where large multilocular shells, of a nature intermediate between the ammonite 

 and nautilite (resembling the ■well-known fossil of Kelloway in Wiltshire), are 

 frequent ; they are covered with a beautiful pearly crust, and are sometimes 

 carried down by the floods into the Volga at Vasil-Soursk. When cut, the 

 interior of these shells is usually found in a delicate state of preservation f. 



the Kremi or fortress, but is not distinctly seen on the other side in the cliffs on the Cazanka. 

 Specimens of it are in the Museum at Oxford. 



* The view from the hill of Simbirsk (Plate 1. fig. 3.) shows the relative situation of the white 

 marl, sand, and black clay. The rocks in the distance are the white central limestone, forming 

 the High Steppe of Pallas, which near Cinghyley rises into the high hills which border the Reach 

 of Samara. 



+ These appear to fall under the genus which Parkinson proposes to call Ammonautilus; — 

 Organic Remains, vol. iii. p. 108. — They certainly are the same which Parkinson mentions at p. 140, 



