•2 
DIENEB : TRIAS OF THE HIMALAYAS. 
Fourteen years have elapsed since the publication of the results of 
the expedition of 1892, in which Griesbach, Middlemiss and I took part. 
Shortly afterwards the study of the sedimentary deposits of the Hima- 
layas was resumed ; areas formerly known only more or less superficially, 
were re-examined in greater detail and a very large amount of new fossil 
material has been obtained. Both the observations in the field, 
whic'i are chiefly due to H. Hayden, A. von Krafft, La Touche, Smith, 
Naetling and Walker, and the subsequent examination of the collections 
have increased our knowledge considerably, particularly so with respect 
to the Trias. While formerly only the sections of Painkhanda (Shal- 
shal cliff, Ban'iiaag cliff) were known in any detail, we have now 
equally detailed ccounts of those in Spiti and considerable additions 
have been made t> our knowledge of those in Eastern Johar and Byans 
and in the region oi the exotic blocks between Malla Johar and Hundes. 
It therefore seems possible now to make an attempt to correlate those 
four different areas. 
Recent researches tend to show that the Trias, far from being de- 
veloped uniformly throughout the length and breadth of the Himalayas, 
has some very marked geographical peculiarities. We can no longer 
characterise any individual section as a " type-section " of the Hima- 
layan Trias. To do so would, indeed, be as incorrect as to speak of a 
particular section in the South-eastern Tirol or in the Salzkammergut 
as a type-section of the Alpine Trias. 
In fact the Himalayan Trias clearly shows those changes of facies 
which are common to most sedimentary deposits of marine origin, and 
which, if not so rapid or abrupt as in the case of the Alpine Trias, are 
yet almost equally marked. This becomes especially evident from a 
comparison of the sections of Byans and Malla Johar with those of Spiti 
and Painkhanda. 
My examination of the fossil collections made by Hayden and A. v. 
Krafft in Spiti and Malla Johar and my revision of A. v. Krafft's 
memoir on the Cephalopoda of the Lower Trias have delayed the writing 
of this paper for a longer period than I had anticipated. This delay, 
however, has enabled me to include many new facts, which were not 
known to Noetling, when publishing his summary of the Trias of Asia 
in Lethcea mesozoica (Vol. I, Pt. 2, Stuttgart, 1905). A direct com- 
parison will, I trust, convince the reader that the present paper has 
not been rendered altogether unnecessary by Noetling's memoir. 
( 203 ) 
