i DIENER : TRIAS O]?* THE HIMALAYAS. 
Leaving aside the horizon of Rhynchonella Griesbadu and the Niti 
limestone, which in thickness is the predominating element of the 
Middle T rias of Painklianda, the rest of the Muschelkalk falls naturally 
into two subdivisions, a lower one about six feet in thickness, consisting 
of thin-bedded, grey limestones, partly alternating with shales (bed 
No. 3), and a higher one (No. 4) reaching a thickness of 20 feet, consist- 
ing of dark grey, regularly bedde^ limestones. In the scenery the 
group No. 3 is often indicated by a softer slope, interrupting the out- 
lines of the steep escarpments above and below. 
The Lower Muschelkalk (group No. 3) constitutes one single strati- 
graphical horizon. There is no definite boundary between the lower beds 
containing ammonites and the higher ones containing brachiopods. As 
we pass upwards in the sections — especially in that of the Bambanag 
cliff, — the ammonites are gradually replaced by brachiopods, according 
to A. V. Krafft's observations. The whole series between the Niti lime- 
stone and the Upper Muschelkalk must therefore be united in one group, 
but it must be understood that the cephalopoda prevail in the lower 
part of the group, and the brachiopoda in the upper. 
The brachiopod fauna of the zone of Spiriferina Stracheyi is very 
uniform in Painkhanda and Spiti. From both regions the following 
three species are known : — 
Spiriferina Stracheyi Salt. 
Spirigera Stoliczkai Bittn. 
Rhynchonella Dieneri Bittn. 
A fourth species, Rhynchonella mutabilis Stol., is hitherto known from 
Spiti only. Three other species of brachiopods, which have been des- 
cribed by Stoliczka in volume V of the Memoirs of the Geological Survey 
of India, are of doubtful position, since it is uncertain whether they 
belong to the Lower or to the Upper Muschelkalk. 
Regarding the cephalopod-fauna of the Lower Muschelkalk, the Spiti 
sections — especially those of Lilang and along the Gyundi river — have 
yielded a considerably larger number of fossils than the sections of 
Painkhanda. 
The following four species, all of which were collected by A. v. 
Krafft and Hayden, are common to both districts : — 
Keyserlingites Dieneri Mojs. 
Dalmatites Ropini Dien. 
( ) 
