390 REV. A. IRVING ON THE DYAS (PERMIAN) 
phical names which had been previously proposed, in his great work*, 
which appeared at Leipzig in 1862; and the name has been gradually 
coming into general use on the Continent since that time. It is not 
merely that the name links together in one post-Carboniferous system 
the two great formations of the Rothliegende and the Zechstein 
(the former a land- and shore-formation, the latter essentially a 
marine deposit), but it has reference also to the fact of aremarkable 
parallelism (much more general and more definitely marked than 
usual) between the middle and lower stages of the Zechstein and the 
conglomeratic series of the Upper Rothliegende, to which further 
reference will be made later on in this paper. Many sections might 
be given to illustrate this, but I shall content myself with a de- 
scription of that represented in fig. J, to which Prof. Geinitz was 
good enough to direct my attention last summer. 
Fig. 1.—Section near Eppignellen (NN. Thuringia), showing the paral- 
lelism between the Upper Rothliegende and the Middle and Lower 
Zechstein. 
Valley of erosion. 
— 
Littoral. 
a. Lower Rothliegende. 
b. Middle and Lower Zechstein including Kupferschiefer and the immediately 
underlying Grauliegende (= ‘‘ Weissliegende” of some writers). 
b'. Upper Rothliegende (granitic conglomerates of the Wartburg, &c.). 
c. Upper Zechstein (with Schizodus Schlotheimi, &c.). 
_ * Werra Railway Tunnel. 
The succession of the strata is seen in open sections, and the 
character of the Upper Rothliegende conglomerate is altogether 
different from that of the well-stratified brecciated sandstones and 
marls of the Lower Rothliegende. 
The main point with which we are at present concerned, how- 
ever, is the true divisional line of the Dyas and Trias. So far from 
there being a natural passage from the one to the other (as Mur- 
chison supposed) there are clear and extensive signs of erosion of the 
Zechstein, upon which the lowest Triassic strata (the Bunterschiefer) 
are superimposed ; and Prof. Geinitz has pointed out to me that the 
same break is observable in South Lancashire, where the Magnesian 
Limestone with Schizodus Schlotheimi (the equivalent of the Platten- 
* ‘Die Dyas oder die Zechsteinformation und das Rothliegende (Permische 
Formation zum Theil),’ von H. B. Geinitz. 
