368 SILUKIA. [Chap. XIV. 
Mongolia, the Kirghis Steppes, and the borders of Chinese Tartary and 
Central Asia, by that enterprising explorer and skilful artist, the late T. W. 
Atkinson, who leads us to believe that, in addition to the numerous eruptive 
rocks of ancient geological date, subaerial volcanos must have existed in 
parts of this wild, extraordinary, and hitherto unexplored rocky region *. 
Grand, therefore, as is the spread of soft and slightly coherent primeval 
rocks throughout Russia-in -Europe, the hard stony tracts of this age 
which extend over the Asiatic regions of the same great Empire are mucj). 
more extensive. 
Eestricting our view to Russia-in-Europe, we see fossiliferous Silurian 
and Devonian rocks rise partially to the surface in the southern provinces 
of Podolia, on the banks of the Dnieper ; and although no rocks of such 
high antiquity have yet been detected in the Caucasian mountains, Devo- 
nian rocks reoccur in the same latitude near Constantinople f , and have 
been recognized by TchihatchefF in several parts of Asia Minor to the 
south of the Elack Sea and are also traced even to the southern flanks 
of Mount Ararat, and thence eastwards into Persia §. 
Looking, therefore, to the most ancient crystalline rocks of Northern 
Scandinavia, which probably represent both the Laurentian and Cambrian 
rocks of Britain and other countries, we know that they have been over- 
lapped successively by those Silurian, Devonian, Carboniferous, and Permian 
strata which occupy an enormous region in Russia. The discovery at Spitz- 
bergen of at least one Permian fossil, identified by Mr. Salter ||, shows 
how widely spread were all these primeval deposits, and how they must 
have been successively accumulated around a nucleus of preexisting 
crystalline rocks. 
* See Atkinson's 1 Oriental and Western Sibe- of Europe completed by M. Dumont shortly be- 
ria,' 1858. - fore his death, showing errata of considerable 
t See Hamilton and Strickland ; Proc. Geol. magnitude in relation to the Caucasian region, 
Soc. Lond. toI. ii. p. 437. The Turkish fossils are most of which pertain to rocks of Secondary and 
of the oldest Devonian age, and represent the Tertiary age, not treated of in this work. He 
Spirifer-schist and - sandstone of the Ehine, which, stated, moreover, that the violet colour which re- 
as well as their equivalent the Lower Old Eed presents the Lower Devonian ('Ehenan' of Du- 
Sandstone of Scotland, are wanting in Eussia. mont) must be struck out as regards the tract 
I Bull. Soc. Ge'ol. France, 2 ser. vol. vii. p. 389. lying between 38° and 47° E. long., all that 
My enterprising friend Pierre de Tchihatcheif, country being occupied by very old rocks and 
who has for the ninth time explored Asia Minor, crystalline slates. In truth, however, the Map of 
visiting tracts which were previously blanks on Dumont, one half of which is taken from the Map 
all maps, exhibited his new geological map of of Eussia-in-Europe and the Ural Mountains by 
the whole region to the British Association at the myself and associates, must not be judged by 
Nottingham Meeting, 1866. Large tracts of meta- such ultra-European inaccuracies. Although the 
morphic rocks which underlie true Devonian rocks classification of the stratified rocks by my late 
will, I anticipate, prove to be of Silurian age. distinguished friend differs from that which I 
§ Abich, Quart. J ourn. Geol. Soc. Lond. 1846, adopt, I much admire the clearness and beauty of 
vol. ii. 2nd pt. p. 96 ; and ' Eussia and the Ural his work. For my own Geological Map of Eu- 
Mountains,' vol. i. p. 652. Prof. Abich also found rope (Johnston), as published with the assistance 
Carboniferous Limestones everywhere overlying of Prof. Nicol, I claim more indulgence from my 
these Devonian rocks, and characterized, too, by friends, as it was hastily issued, and contains 
a small Fusulina, of a species distinct from that many errors of detail, and is now much behind 
found in Eussia. The memoir he has published, the knowledge of the day. In extending his ob- 
and particularly a large work which, I rejoice servations to the eastward, M. Hommaire de Hell 
to think, he is now preparing, under the auspices discovered Devonian rocks in Persia, where they 
of the Bussian Government, must throw great form the axis of the Elburz chain and the southern 
light on the physical structure of the whole chain slopes of the mountains of Tchihennene, and are 
of the Caucasus. In a memoir received when highly fossiliferous in the valley of Tuva. (Bull, 
the last edition was coming out, M. Abich Soc. Ge'ol. Fr. vol. vii. p. 500.) 
offered several critical remarks on the Map || Quart. Journ. Geol. Soc. vol. xvi. pp. 440, 441. 
