RUSSIAN DIVISIONS INTO EOCENE, MIOCENE AND ARALO-C ASPI AN . 283 
that certain shells which occur in strata near Mecklenburgh, above the brown coal 
maybe referred to the calcaire grossier. On the whole, therefore, we are disposed 
to believe, that a large portion of Northern Germany and Poland is covered by 
strata of the same age as those which are considered Eocene in the basin of Mayence. 
The western portion of our Map is coloured upon this principle (No. 8). 
In relation to Russia, there seems to be no doubt that strata of the older tertiary 
age range up to the city of Kief on the Dnieper, where one of us has observed 
them. Thence, if not continuously prolonged to the east, upon the Dnieper they 
reappear at Butschak, lower down the same river, where they were detected by 
M. Dubois' ; and in the environs of Simbirsk they have been noticed by M. Jasi- 
koff. By our own observations we show the presence of fossiliferous deposits of like 
age upon the Lower Volga, and thus, it is clear, that the oldest tertiary deposits 
strictly so termed, do exist in Russia, though their exact boundaries and limits 
have yet to be defined. 
Of the existence of Miocene deposits (No. 9.) there are also abundant examples, 
in broad horizontal expanses of limestones, marls and sands, which ranging from 
the upper part of the valley of the Vistula on the west, spread out in vast sheets 
over the governments of Volhynia, Podolia, and Bessarabia, to near the western 
shores of the Black Sea and the low country north of Odessa, where they subside 
beneath other deposits of a younger age. With the detailed relations of such masses 
throughout the greater part of this low region, our acquaintance is chiefly limited, 
to the southern districts of Poland on the west, and to the neighbourhood of Odessa 
and the edges of the Black Sea and Sea of Azof on the east, including parts of 
the Crimsea. . , , 
A glance at the Map will show the general line of separation between the older 
tertiary (No. 8.) and the miocene deposits (No. 9.). In Poland they ate mle< 
by an axis of ancient rocks, chiefly Devonian, which ranges from west-nor h-west 
to east-south-east in the environs of Kielce ; in Podolia and Volhynia by the gra- 
ITs eppe and still further to the east by the coa, -field of the Donet, Agreemg 
wift M Dubois de Montperenx, who has pointed out the drst.nct.ons ,n Volkyma 
I d Podolia. between these two great tertiary zones, we regret that : .< has not been ... 
1 power to lay down their exact geographical limits throughout tl.e.r ent.re range. 
We simply propose to indicate natural groups, the exact boundar.es of wh.cl. can 
. See . letter of M. v. Each. Bulletin de 1. Sec. (Mol. de France, vol. vii. p.U7 . and Neue, Jahrbuch 
vor. Leonh., &c. 1836, p.359. 
