TRIASSIC SYSTEM. 
69 
In view of the above, the upper boundary of the lower trias will lie 
somewhat higher than has hitherto been supposed, and must be taken 
somewhere above the middle of the nodular limestone. Plate IV 
represents a section of the lower and middle trias in the hills to the 
south-east of Muth. A comparison of this figure with that to be found 
on page 546 of Professor Diener's account of his expedition to the 
Himalayas in 1892^ will show that the lithological succession of this 
part of the trias of Spiti is almost identical with that of Painkhanda, 
but the interpretation given above of the Spiti sequence differs from 
that given by Professor Diener for the Shalshal cliff. 
The Productus shales, Otoceras beds and Hedenstraemia beds — 
Diener's " Subrobustus beds" in part— are the same in both sections 
while his " Subrobustus beds " include the horizon of Pseudomonotis 
himaica, which fossil was first discovered by him in the Shalshal cliff. 
His subdivision (4), which he names the "horizon of Sibiritei, prah- 
lada," is said by him to contain also Rhynchonella griesbachi and 
Spiriferina stracheyi, but this association of the two last-named 
brachiopods was considered by Bittner as highly improbable.^ These 
doubts were subsequently confirmed by Dr. von Krafft, who had an 
opportunity of studying Diener's original section on the spot : he found 
that the section was in every respect similar to those of Spiti, and that 
there were two brachiopod-bearing horizons, viz., that of Spiriferina 
stracheyi above, and that of Rhynchonella griesbachi h&\ow, the nodu- 
lar limestone, nor could he find in the lower horizon any trace of the 
brachiopods so common in the upper, while the horizon of Spiriferina 
stracheyi was found to correspond in every respect with the same 
horizon in Spiti. At that time the lower horizon had not been detected 
in Spiti, and on Dr. von Krafft's suggestion the present writer made a 
careful search for it and succeeded in finding it at the base of the nodular 
limestone, in the exact position in which it was found hy Dr. von Krafift 
at the Shalshal cliff ; in Spiti, however, it is poorly developed and 
fossils are scarce, and it had consequently been previously overlooked. 
' Denkschrift. der k. Akad., Wien, LXII, 1895. 
• Jahrbuch k. k. Geol. Reichsanstalt, XLVIIl, 1899, p. 692. 
( 69 ) 
