400 REV. A. IRVING ON THE DYAS (PERMIAN) 
waters. Extensive continental conditions must have prevailed*. 
The ancient rocks of the Bohemian region are probably the skeleton 
of such dry land as then existed. In travelling in that country and 
in the adjacent regions of Upper Austria one hardly fails to be 
struck with the resemblance of its mountain-regions to the moun- 
tains of Wales and Scotland. This resemblance is not a superficial 
one; in both cases we have the worn-down stumps of more ancient 
mountain-systems of much greater dimensions than those which 
exist to-day ft. The elevation of Bohemia and Upper Austria, a 
region which is skirted on the south by the Danube from Passau to 
Krems, must have taken place in times long anterior to the upheaval 
of the Alps, and dates at least as far back as post-Carboniferous 
times. Since then, while many thousands of feet of Mesozoic strata 
were being deposited at the bottom of the sea, in what is now the 
region of the Alps, the Bohemian region has been sufferimg denuda- 
tion. The Bohemian coal-field, which yields true seam-coal of 
Carboniferous Age, is a remnant of the deposits of that early period 
in Central Europe; and another remnant of the same once more 
extensive deposit is found in the coal-field of Saxony, where one 
seam of coal attains the enormous thickness of 24 feet. The Roth- 
liegende of the kingdom of Saxony and of Bohemia, which is of huge 
proportions, represents nearly the whole of the post-Carboniferous 
deposits on the northern flank of the Bohemian region, which must 
be considered as extending so far north as to include the country 
about Dresdent. In the shallow arms of the sea which washed the 
northern side of this ancient and now much-denuded remnant of an 
old continent, the coarse deposits of the Rothliegende were accumu- 
lated, deriving their materials mainly from the waste of the igneous, 
Cambrian, Silurian, and Carboniferous rocks of that region, as may 
be seen by an examination of their contents. This condition of 
things would seem to have continued through almost the whole post- 
Carboniferous period on the northern flanks of the ancient Bohemian 
region, while further to the west and north, in Thuringia and in the 
country about the Hartz, the major portion of the Zechstein strata 
were being deposited under conditions more or less truly marine. 
Towards the close of the Dyassic period things seem to have settled 
down and become more quiescent, a slight subsidence of the whole ~ 
area occurring, since the upper member of the Zechstein (Platten- 
dolomit) which elsewhere more generally overlies the middle and 
lower members of the Zechstein group, rests generally in the king- 
dom of Saxony upon the Rothliegende, the replacement of the 
* Of. Dr. H. Trautschold ‘‘ On the periodical movements of continents,” Geol. 
Mag. Nov. 1883. Jam glad to find some of the ideas which I have ventured 
to put forward here, agreeing with some of those of Dr. Trautschold, whose 
paper I read after this was written. 
Tt Cf. Q.J.G.8., Feb. 1883, p. 79; also Prof. Lapworth, Geol. Mag. Dee. ii. 
VOl.jxegpoglods r; 
{ Dr. Trautschold (zbid.) notices that the absence of several systems of 
marine sediments speaks in favour of a long continental period in Russia, in the 
Government of Moscow, from the end of the Carboniferous period to the middle 
of the Oolitic period. 
