4.8 
DIENKR : TRIAS OF TTTK TTTMALAYAS. 
with the Trias by Diener, but those two authors are entirely 
in accord in acknowledging the fact that there is a gradual transi- 
tion of the deposits from the Ruling shales to the Hedenstroemia beds, 
without any break or unconformity. 
Since the discussion of the Permo-Triassic problem in the Himalayas 
had come to a preliminary close in 1905, much new evidence has been 
gathered from an examination of the Triassic fossils from Spiti and 
Painkhanda by A. v. Krafft and C. Diener, from the study of the 
Meekoceras fauna in California and Idaho by J. P. Smith, and from the 
discovery of a rich Permian fauna in the Bellerophon limestone of 
Carniola by Kossmat and Schellwien. A sufficient number of facts, I 
believe, has been accumulated now to enable us to delimit the Permian 
and Triassic systems on the same basis 'in the Eastern Alps and in the 
Himalayas. 
Noetling has laid special stress on the absence of any defined 
break in the series between the Hedenstroemia beds and the Productus 
shales. Nevertheless he draws his boundary below the Meekoceras beds, 
not above them, where the lithological change is certainly marked more 
sharply. But I shall not insist on this objection to his division of the 
two systems, because in my opinion lithological affinities can never give 
a clue to the true position of horizons in the standard stratigraphical 
scale. The object of correlation is and has been to bring newly discovered 
horizons into their proper places in systematic classifications already 
established. Such correlations, however, can be made with any precision 
on palceontological evidence only, the apparent lithological affinity of two 
strata never being a safe means for their association in one strati- 
graphical subdivision. 
A remarkable instance may be quoted here regarding the question 
of the Permo-Triassic boundary in the Eastern Alps, which in many 
respects is similar to the same problem in India. 
There is no unconformity between the Permian Bellerophonkalk and 
the shales of the lower Werfen (Seis) beds, but the lithological contrast 
between the two groups is rather sharply marked, considerably more so, 
as a rule, than between the Productus shales and the Otoceras stage. 
Nevertheless sections have been found, where the Bellerophon limestone 
passes gradually into the overlying shales. Now in the vicinity of 
Sarajevo a very interesting section has been described by E. Kittl (Geolo- 
gic der Umgebung von Sarajevo. Jahrb. K. K. Geol. Reichsansi., 1904, 
( 249 ) 
