DIENER : TRIAS OF THE HIMALAYAS. 
stage. Being obliged to acknowledge the fact, he attempts to lessen its 
stratigraphical value by a hypothesis, which is, perhaps, the best argu- 
ment that could be produced against an adoption of his views. 
As an explanation of the sudden extinction of Palaeozoic brachio- 
pods in the Salt Range he suggests an increase of the temperature 
of the sea, which he believes to have advanced from north to south. 
Thus the Palaeozoic brachiopods still persisted in the Salt Range after 
they had already been extinguished in the Himalayas. The biological 
change was not synchronous in the two regions and the line of demar- 
cation, which in the Salt Range separates the two systems, does not 
separate them in the Himalayas. 
When we examine this argument critically, we find that the 
theory to account for the supposed difference in the periods of extinc- 
tion of the Palaeozoic brachiopods in the Himalayas and in the Salt 
Range has no solid foundation whatever. But even if the validity of 
this theory should be conceded, there was the error at the start that 
Noetling has mistaken synchronism for homotaxis. It is on homo- 
taxis, however, not on synchronism, that all stratigraphical correlation 
must needs be based. 
With this negative evidence of the absence of Palaeozoic brachiopods 
the positive evidence of a faunula of Triassic lamellibranclis agrees. From 
the unquestionable affinity or even identity of some Ammonoidea and 
Lamellibranchiata in the Indian Otoceras fauna with species of the 
American Meekoceras and of the Alpine Seis beds, there is scarcely room 
to doubt that the Otoceras stage is, indeed, of Triassic age. 
We are led to the same conclusion by the method of comparing the 
Permo-Triassic sequence of the Himalayas with that of the Eastern Alps, 
where, exactly as in India, the gap between the two systems is filled up 
by an uninterrupted series of marine deposits, ranging from the Groeden 
sandstones into the Werfen beds without the slightest trace of an 
unconformity. The Permian age of the Alpine Bellerophon Limestone 
having been ascertained, the question arises, whether it should be 
correlated with the Kuling shales and Upper Productus Limestone or 
with the Otoceras beds. 
Such faunistic affinities as exist between the Otoceras beds and 
the corresponding Alpine deposits point in the direction of the Seis 
beds, not of the BeUerophonkalk, as has been demonstrated by Bittner. 
( 253 ) 
