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from those published by Sowerby from the London clay of Bognor 
and Hants, such as Cuculle@a decussata, Venericardia planicosta, 
Calyptrea trochiformis, Crassatella sulcata, Turritella edita, &c. 
The middle tertiary or miocene strata are spread, it is well known, 
over large tracts in Volhynia and Podolia, in which countries they 
have been described or alluded to by Prof. Eichwald, M. Dubois de 
Montpereux, 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 phenomena 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 comparative- 
ly 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 Mactre, 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 Crimza and the neighbourhood of 
Odessa, described by M. deVerneuil (See Trans. Geol. Soc. of France, 
vol, ii. 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 of 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, &c.—It is shown that the mammoth alluvia are anaiogous 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. 
VOL. Ill, PART II. 3N 
