70 Geological Society. 



Montperoux, Major Blode, and others. Distinctions are, however, 

 drawn between the more ancient tertiary strata, such as those of 

 Antipofka and other places, and the recent Caspian shelly sands 

 which cover the Steppes, the former having constituted a portion of 

 the ancient shores of a more widely spread Caspian sea. The au- 

 thors also entirely discard from residuary phaenomena due to the 

 presence and retirement of these Caspian waters, the existence of 

 certain great subterranean masses of rock-salt and salt-springs which 

 issue from the bowels of the earth, both of which have their seat in 

 purely marine deposits of much higher antiquity, chiefly Permian, 

 and which can never be referred to the desiccation of comparatively 

 modern, brackish, inland seas. 



The pliocene and post-pliocene strata, occupy a very large region 

 in Southern Russia. The inferior division of this group is well ex- 

 posed in the lowest part of the cliffs at Taganrog, on the sea of Azof, 

 where beds of white and yellow limestone contain several species of 

 Cardium, a Buccinum and large Mactrse, all of marine origin. The 

 superior members, often reposing on sands and siliceous grits, con- 

 stitute the widely spread " Steppe limestone," in which are many 

 remains of Mollusca that must have lived in brackish seas. 



These beds, as seen at Novo Tcherkask, the capital of the Don 

 Cossacks, and adjacent places, are considered to be the extension 

 of similar shelly deposits in the Crimaea and the neighbourhood of 

 Odessa, described by M. deVerneuil (See Trans. Geol. Soc. of France, 

 vol. iii.p. 1.). 



The vast flat steppes of Astrachan traversed by Count Keyserling, 

 who rejoined his companions at Sarepta, are proved, as suggested 

 by Pallas, to have been the abode of the adjacent Caspian Sea at a 

 comparatively modern period ; and in confirmation of this view, it is 

 stated, that not only the low country is covered with shells, but that 

 the cliffs at Monte Bogdo, which rise out above this steppe, are also 

 corroded to a certain height in the same way as sandstones of simi- 

 lar nature are affected by the surge of the present seas. 



Superficial Detritus, Bones of Extinct Mammalia, Northern Boul- 

 ders, fyc. — It is shown that the mammoth alluvia are analogous to 

 those of other countries in indicating, over large areas, a period when 

 elephants, rhinoceroses and other gigantic animals of species now 

 extinct, inhabited the surface of the earth not far from the spots 

 where they are now interred, their bones, as demonstrated by their 

 condition as well as by the matrix in which they lie, not having un- 

 dergone distant transport. This subject will be again considered 

 in a sketch of the Ural mountains, but in the mean time, lists of 

 the animals, some of them peculiar to Russia, which are preserved 

 in the museums of Moscow and St. Petersburgh, were given. 



Lastly, new data are offered in respect to the southernmost 

 limit of the northern blocks described on a previous occasion 

 (vol. xix. p. 496), and their further advance to the south in some 

 situations than in others, is attributed to the form of the present con- 

 tinent of Russia in Europe, nearly all of which, it is presumed, was 

 under the sea during the distribution of these boulders. 



