750 
instances, are even traceable over small ridges of intrusive and altered 
rocks from veins whence the detritus was doubtless derived, and ac- 
cumulated in its present state at the period when the large mammals 
were destroyed. Numerous sections are given at Berosofsk, Soi- 
manofski Zavod, and notably from the environs of Miask and Cos- 
satchi Datchi, all of which tend to establish these views, as well as 
those of the alteration, mineralization and crystallization of the 
palzozoic strata by the intrusion of igneous matter, and prove that 
the alluvia were collected anterior to the existing epoch. Some 
of the gold alluvia are exclusively composed of carboniferous lime- 
stone replete with fossils (Cossatchi Datchi). 
In concluding this sketch of the Ural mountains, the authors ad- 
vert to the remarkable fact, that all the superficial detritus is local, 
and that no large boulders or blocks transported from afar are 
visible either in the chain or in the Jow countries on its flanks; and 
they also state, that they nowhere observed among the higher por- 
tions of the mountains any traces of those scratches or polishings of 
the rock which are common in some parts of Europe, and which 
are supposed to have been produced by glacial action. . 
Original maps and sections of the districts around the mining 
establishments of Bogoslofsk, Turimsk and Blagod at Ekaterinburg, 
Soimanofsk, Zlataoust and Miask, prepared by the officers of the 
Imperial School of Mines, were exhibited, as well as a map of the 
North Ural to 65° N. lat., drawn by Strajefski, together with a most 
elaborate geographical map of the South Ural, executed by orders 
of General Perovski, under the superintendence of the officers of 
the staff of his government, directed by General Rakosofski*. From 
all these documents and others published in the volumes of the 
‘ Journal of the School of Mines,’ combined with their own ob- 
servations, the authors have coloured geologically the map of Hum- 
boldt, a reduction of the chief features of which will appear in a 
map now in progress, which will accompany their forthcoming work 
on Russia and the Ural mountains. 
General Conclusions.—In greatly extending the knowledge which 
they had previously acquired, the survey of last year has enabled 
the authors to modify their earlier views concerning the equivalents 
of some of the strata of Russia in Europe. With respect to their 
former account of the great tripartite palzozoic series of beds 
which covers such large portions of Northern Russia, they have 
nothing to retract. On the contrary, by adding to their previous lists 
a great number of typical organic remains well known in Western 
Europe, they are still more convinced of the accuracy of their first 
classification, and of the existence of large zones of Silurian, Devo- 
nian and carboniferous rocks, clearly separated from each other by 
their order and their imbedded fossils. 
The newly discovered dome of Devonian rocks in the centre of 
* This map is illustrated by a description of the physical features of 
South Ural from the pen of M. Khanikof, which Mr. Murchison has com- 
municated to the Royal Geographical Society of Londen. 
