rOKT?F,T, ATTON OF TTTF T.OWKTl TRTAS. 
agree very closely, altliougli their distance apart is 130 miles. The 
Ijower Trias in both districts consists oi' darlc limestones alternating 
witli shales. In the lower division, following above the Permian 
Killing, or Produotus, shales, black limestones predominate. In the 
upper division the limestones are of a dark grey colour and thin- bedded. 
In Spiti the upper division is of considerably greater thickness than the 
lower one, 30 feet to (3 feet, whereas in the 8halshal clif? tiiis proportion 
is only 30 feet to 21 feet. The lithological boundary, although not 
very sharp, is well marked both in the sections of Painkhanda and 
of Spiti. 
The lower division contains three fossiliferous horizons in Spiti and 
four in Painkhanda, but in both regions the topmost horizon only has 
yielded a fauna which is distinguished from that of the lower horizons. 
The lower horizons represent the Otoceras beds sensu stricto. 
In 1901 two different zones were distinguished in the Otoceras beds 
of Painkhanda by Noetling,' the lower containing the fauna of 
Otoceras Woodivardi, the upper being characterised by the predominance 
of Ophiceras libeficuni. In 1904 a third zone was added to them 
by Noetling,'- who consequently distinguished among the Otoceras beds 
the following three zones : — 
3. Zone of Ophiceras tiheticum Griesb. 
2. ,. ,, Episayeceras Dalailamoe Dien. 
1. ,, Otoceras Woodwardi Griesb. 
Noethng's statement that those ' three zones are sharply separated 
faunistically " is contradictory to the facts, as I have tried to show in 
my memoir on the stratigraphical position of the Otoceras beds.'' A 
distinction of separate palaeontological zones in the uniform fauna of 
the Otoceras stage is purely artificial. There is no element in the fauna 
of either horizon which might justify its palaeontological indejiendence 
from the others. ' They are minute local subdivisions of one single zone 
only. 
Those local subdivisions can also be recognised in the section of 
Lilang, Spiti, although their faunae do not correspond exactly. The 
1 F. Noetling in Lethcea palceozoica, Vol. II. Dyas, p. 656. 
- F. Noetling, Neues Jnkrb. f. Min., Beil. Bd. XVIII, 1904, and Lethoa mes., 
Asiatische Trias, 1. e., p. 132. 
3 C. Diener : Ueber die stratigrapliische Stellung der Otocera.s beds des Himalaya , 
Centralbl. f. Min., 1905, p. 2. 
