ON THE GEOLOGY OF RUSSIA IN EUROPE. 
209 
which several workable seams occur ; though in this comparison 
it must be stated, that the Russian beds contain much more coal 
than the British strata. But even if we admit that^ to some ex- 
tent, there is a similarity in the carboniferous rocks of South 
Russia and the Low Countries, in their being both flanked by 
cretaceous deposits, we must also not omit to recognise a great 
discrepancy, through the presence in the one case of overlying 
strata of the age of Zechstein, and in the other by the total ab- 
sence of that deposit. 
To considerations of theoretical importance concerning the 
changes which the surface of Southern Russia may have under- 
gone, and which are ably put forth by M. Le Play, I will not at 
present advert ; reserving my views on these points for the con- 
cluding chapters of the work upon Russia, when all the ele- 
ments which my friends and myself can bring together shall 
have been laid before our readers, to enable them to see the 
grounds upon which the conclusions are based. 
For the present, then, I take leave of this volume of M. Le 
Play, which, though it contains some views of positive geology 
from which I differ, must still be regarded as an important ad- 
dition to the records of physical science, and as possessing much 
more the character of a good monographic description of a 
given tract in Russia, than anything which, from the extensive 
nature of our researches, my friends and myself will ever be en- 
abled to offer. 
Permian Rocks. — On its eastern frontier, far removed from 
the tract to which allusion has been made, the uppermost mem- 
ber of the carboniferous limestones of Northern and Central 
Russia, distinguished by the presence of multitudes of the fora- 
minifer FusuUna, is succeeded by the most widely spread of the 
Russian systems ; to which, from its occupying the whole of the 
ancient kingdom of Permia, we have assigned the name of Per- 
mian. You have been told, that this vast group is composed of 
limestones, marls^ great masses of gypsum, rock-salt and re- 
