110 
DIENEE : TEIAS OF THE HIMALAYAS. 
been offered by Suess and in a somewhat altered form by A. v. Krafft, 
but which is not supported by convincing reasons, is only able to 
explain the rapid change of facics between the Tibetan and Himalayan 
series, but leaves the agreement of the Tibetan and Alpine series during 
the carnic and liassic periods unexplained. 
IV — THE CEPHALOPOD HORIZONS OF THE HIMALAYAN 
TRIAS. 
The Trias of the Himalayas has been termed a cephalopod-bearing 
facies by several authors. But this statement can be made only with 
great reserve. It is true that some horizons are, indeed, con- 
spicuous by an abundance of Cephalopoda, which is not surpassed by 
any in the Alps. But those horizons rule, of small thickness 
and separated by mighty masses of rocks very poor in fossils. 
The cephalopod-bearing beds come to a close rather abruptly in the 
lower noric stage. In the higher divisions of this stage ammonites are 
of the rarest occurrence, and in the Indian equivalents of the Alpine 
Dachsteinkalk they are wanting altogether. From their fossils the 
enormous mass of shales, sandstones, quartzites, dolomites and lime- 
stones, which follow above the Juvavites beds of Spiti or above the 
Halorites limestone in Painkhanda, might be determined as a brachio- 
pod or a bivalve facies, but certainly not as a cephalopod facies. 
Even in the Tibetan region of exotic blocks, where the fauna? of the 
Lower and Middle Triassic, carnic and liassic beds are represented 
almost exclusively by cephalopods, the grey limestones of the noric or 
rhaetic stages are practically unfossiliferous. They have not yet 
yielded any ammonites. 
It is necessary to state this, in order to prevent the student of the 
Himalayan Trias from forming exaggerated ideas on the abundance of 
cephalopod-bearing horizons. Those horizons are undoubtedly of the 
highest stratigraphical and faunistic importance, but are of small 
thickness in comparison with the unfossiliferous rocks, especially so in 
the Upper Trias. 
In the Himalayan Trias ten cephalopod-bearing horizons have been 
distinguished by Noetling (Asiatische Trias, I.e., p. 177), who correlated 
the Otoceras beds with the Permian system. 
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