50 
DIENER : TRIAS OF THE HIMALAYAS. 
been described from the fauna of Jiilfa, are leading fossils of the Upper 
Permian, but the ijenus Otoceras is not. 
A similar remark applies to Epimgeceras Dalailamce. The genus 
Episageceras in Noetling's interpretation is represented by three species 
only. Episageceras Wi/nnei Waag., from the Upper Productus lime- 
stone of the Salt Range, E. Dalailamoe Dien., from the Otoceras beds of 
the Himalayas, E. latidorsatum Noetling from the zone of Prionolohus 
rotundatus (lowest Ceratite marls) of the Salt Range. In its sutures 
E. Dalailamoe agrees more nearly with the Permian E. Wi/nnei than 
with the Triassic E. latidorsatum. This affinity is considered sufficient 
for claiming a Permian age iov E. JQalailanios. But this conclusion far 
exceeds the limit of the true relations of the elements of organic form to 
geological age, and the specific discrepancy between E. Dalailamoe and 
E. Wynnei cannot be corrected by interpreting E. Dalailamoe as a repre- 
sentative of a Permian group of forms in the face of the absence of all 
faunal guides pointing to a Permian age of the Otoceras beds. 
By this method of correlation the Permo-Triassic problem in the 
Himalayas has not been solved but simply reserved. 
Noetling looks upon the genus Otoceras and the group of Episage- 
ceras Dalailamoe as leading fossils of the Permian system and infers from 
their presence in the Indian Otoceras beds a Permian age for that stage. 
But in reality it is this character of the two ammonites quoted above 
as leading fossils of the Permian system, which ought to be proved first 
and this can only be done with reliable evidence of the Permian age of 
the Otoceras beds. Provided the Otoceras beds of India be really 
Permian, then, but only then, Otoceras is indeed a Permian genus. 
Otherwise it would be common to the Permian and the Trias, as are 
Xenodiscus and Hungarites. No diagnosis of the age of the formation 
can be based on the presence of Otoceras, but the stratigraphical value 
of the genus depends on the way in which the problem of the Otoceras 
beds is solved. 
All mistakes in the correlation of the Indian Otoceras beds were an 
outcome of the faultiness of this method. It has therefore been neces- 
sary to go into full details, since a general reliance among European 
geologists upon Noetling's authority still stands in the way of the 
acceptance of the truth. 
Positive palaeontological evidence is decidedly contradictory to the 
assumption of a Permian age for the Indian Otoceras beds. The general 
( -^-^l ) 
