PREFACE. 
Xlll 
neuil paid to England. As it advanced, however, Mr. Murchison per- 
ceived, that though well-grounded in the great features of classification, 
further researches in the field were called for, before the design could 
be satisfactorily executed. Aware that his colleague Count Kej serling 
bad resolved to explore during the following year (1843) the almost 
untrodden regions of north-eastern Russia, watered hy the great river 
Petchora, he naturally sought to defer v the publication until that survey 
should be completed ; since many original geographical and geological 
features must in that way he obtained— features now, for the first time, 
correctly delineated upon their map, and which exhibit the previously 
unknown Timan Range stretching to the icy sea through a region in- 
habited only by Samoyedes, and a great portion of it beyond the limits 
of arboreal vegetation. Whilst, therefore, Count Keyserling was thus 
occupied in such north-eastern wilds, Mr. Murchison revisited several 
parts of Germany, exploring many tracts which he had not previously 
seen, more correctly to determine the true relations of their palteozoic 
deposits to those of the British Isles on the one hand, and to those of 
Russia on the other • his principal object being to define with greater 
accuracy the equivalents of the Permian system, and at the same time to 
become acquainted with the structure of Poland and those edges of the 
Carpathians which border upon the Russian empire. 
Another year passed over, and the work was already considerably 
advanced, both as respected this first or English volume, and the second 
01 Fiench volume, in which the chief organic remains are described by 
M. E. de Verneuil 1 . But still it was felt, that without a survey of the 
Scandinavian rocks which form the north-western girdle of Russia, the 
book would necessarily be incomplete ; and accordingly the summer of 
1844 was devoted to that purpose. This last journey has, indeed, been 
even more productive of valuable knowledge than was anticipated ; for 
1 In 1843, M. de Verneuil, accompanied by Vicomte d’Archiac, examined the paleozoic rocks of 
ormandy, Brittany, &c., with a view to general conclusions and results; and in 1844 a severe attack 
° lUness alone prevented his joining Mr. Murchison in the examination of Norway and Sweden. 
C 
