DESCRIPTION OF THE PLATES IN YOL. I. 
655 
II.— COLOURED SECTIONS. 
PLATE I. 
Phis Plate refers exclusively to the Carboniferous region between the Don and the Dnieper, 
usually known as the coal-field of the Donetz. (See detailed account of, pp. 89 et seg.) 
PLATES II. to IV. 
these three long coloured Plates represent a series of transverse sections of the North and 
South Ural Mountains on various parallels of latitude, as explained in the text from 
pp. 353 to 403, and pp, 420 to 461. As each coloured section has a separate title and is 
fully explained in the text and on the copper-plates, any repetition of description is here 
unnecessary. (At the heading of Chap. XVIII. p. 420, Plate III. has, through an omis- 
sion, not been referred to.) 
PLATE V. 
Contains a section from the low tracts on the west, up to the axis of the Arctic Ural, and 
other sections across the Timan range and adjacent country. (See pp. 404 et seg.) 
III.— MAPS. 
PLATES VI. and VII. 
The General Map (PI. VI.) was commenced in 1840, after our first journey to Russia, and in 
its earliest state (when exhibited at the British Association for the Advancement of 
Science in the autumn of that year) contained the chief demarcations of the older palaeo- 
zoic formations only, as extending from south-west to north-east 1 . It was not, however, 
until after our much longer continued and more extensive explorations of 1841, that we 
were enabled to colour a general Map of Russia, a copy of which we laid before His 
Imperial Majesty in the autumn of that year, accompanied by a long section across the 
empire from south to north, of which the figure at the bottom of the Plate is a reduced 
copy. The existence of a great dome-shaped mass of Devonian rocks around Orel, which 
forms so prominent a feature in that section, was, indeed, observed by us on two parallels, 
in our journey from south to north during the autumn of that year, in which it was also 
1 In the Preface we have already spoken of a geological map of Russia compiled by Colonel Helmer- 
sen (St. Petersburgh, 1841), who in bis account of its construction gives due merit to every contributor, 
from the early days of Strangways to the period of our first visit when we travelled to Archangel and 
across the province of Vologda (see Preface). Another map, also embracing our first year’s results, was 
published by M. Adolph Erman in his Archiv fur Russland (Berlin), 1 841, a comparison of which with our 
present maps will show the progress made since that time. 
4 P 2 
