A general Review of the Geology of Russia. 157 
the characters of the cretaceous formation of the north of Europe. 
No part of it assumes the type which it possesses in Southern 
Europe, in Africa, Asia, and which is usually denominated the 
Mediterranean type. 
he nummulite limestone, which in the Crimea reposes on the 
white chalk with Belemnites mucronatus, does not show itself in 
any other part of Russia. 
Passing now to the tertiary formation, M. de Verneuil described 
the distribution of these different formations in proceeding from the 
north to the south. The great granitic axis which extends from 
Volhynia to Donetz appears to be the dividing line between the 
great eocene and miocene groups. It is, mdeed, on the north 
side of this zone that the eocene deposits are found. ‘The ter- 
tiary formation in the Volhynian-Podolian part of the plateaux de- 
scribed by M. Dubois of Montpereux, seems to be the continua- - 
tion of the miocene deposites of Transylvania and Austria; it as- 
sumes, however, rather a different aspect as it advances easterly 
towards Kischenef, Marioupol and 'Taganroy. Lastly, a still 
more extensive and considerable deposit succeeds, viz. that 
which the authors have called “Aralo-Caspian,” since it~ has 
been formed under the waters of a sea, the general area of which 
occupies the present basin of the Caspian and Aral seas. This 
immense sheet of water, of which these two seas are but the re- 
mains, extended even to the western shore of the North sea, and 
had no communication with the Mediterranean sea or the ocean. 
In consequence of its being an inland and isolated sea, it was 
peopled by a peculiar fauna, which reminds us of the present in- 
habitants of the Caspian sea. How has this great mass of wa- 
ters in part flowed away so as to leave only the actual seas ? 
Why are these limestones, which were deposited there, and which 
now form almost all the southern shore of the Black sea, now 
found ata height from 200 to 300 feet above the level of the 
existing waters?) Anomalies like these can only be explained 
by supposing that there existed vertical movements of the sur- 
face, which disturbed but little the horizontality of the beds. 
The submersion of a great part of Russia at the termination of 
the tertiary and diluvial period appears to have been the result of 
these phenomena. . italian: Copsey 
communication of the waters of the Mediterranean with 
the basin occupied at present by the Black sea has had the effect 
to give to the fauna of this formation in that direction, a charac 
ter more or less oceanic, but, certainly, very different from that 
of the Aralo-Caspian district. Indeed we find a very anomalous 
result; for, though the shores of the Black sea are formed of 
pliocene deposits, yet amongst the fossil shells of that region, 
there is not a single species identical with any inhabiting the pres- 
ent Black sea. : 
