A general Review of the Geology of Russia. 159 
system from the fragments of fossils found there. These are 
the most ancient rocks of the Ural where there is nothing that 
is comparable to the gneiss and granite of Scandinavia. The 
granites of this chain are more recent and have burst through its 
eastern dislocations, but have not formed its principal summits. 
It is on the same side that most of the igneous rocks are found, 
as well as the rich metallic veins which accompany them, to- 
Devonian and Silurian systems. 
The secondary formations do not penetrate into the Ural. 
Wherever the Jurassic formation approaches this chain, either on 
the north near the 64° of latitude, or on the south near Tanalyzk 
and Orenburg, it always preserves its horizontality. ‘There is no 
doubt that the first elevation of the Ural, and that to which it 
owes its principal bearing, preceded the Jurassic epoch. Indeed 
there is reason to believe that it was even anterior to the Perm- 
ian deposits. The subsequent movements have taken place, 
without doubt, after the accumulation of the cupreous freestones 
of the Permian system, and were of sufficient magnitude to 
modify the position of the axis, and to divide the lines of the 
previous water-shed ; for the beds of copper, whence have been 
derived the cupreous waters that impregnated the Permian d 
posits lying to the west of the Ural, are situated on the eastern 
slope of that range of mountains. 
The paleontology of Russia has been treated of as fully as 
the present state of that department of science will permit. ‘The 
different transformations which it underwent up to that time. 
nsdale, to whom the Polypifera were confided, has described 
oe species with great judgment, in the appendix to the 
ume . 
wi 
est possible ision, the authors have availed themselves of all 
the light wiais the most competent men have been able to 
throw on each branch. Reserving that which concerned the pa- 
