TRIASSlC SYSTEM. 67 
This horizon, which has hitherto been regarded as the base of the 
muschelkalk, is overlain by a bed, about 60 feet 
Nodular limestone. ^^.^^^^ ^^^^^^ nodular limestone, containing 
hardly any fossils, those which occur being usually too badly preserved 
for determination. 
In his paper already quoted Professor Diener states' that in addi- 
tion to the species mentioned above, the beds 
Boundary between . , , , . t ? • 1 1 ■ u 1 1 
lower trias and mus- \\\\\\ Rhynchonella griesbachi had yielded also 
chelkalk. ^^le following forms (determined by the late 
Dr. A. Bittner :— 
Spiriferina stracheyi, Salter. 
Retzia n. sp. ( = R. himaica, Bittner). 
Spirigera, n. sp. ( = S. stoliczkai, Bittner). 
Although the band with Spiriferina stracheyi is very well deve- 
loped and highly fossiliferous in all muschelkalk sections in Spiti, yet 
in spite of most careful search, neither Dr. von Krafft nor the present 
writer could find in it any trace of Rhynchonella griesbachi, but sub- 
sequently the latter species was found by Dr. von Krafft in Kumaon in 
the bed immediately below the nodular limestone ; the two brachiopod- 
bearing horizons being thus separated from one another by a vertical 
distance of about 70 feet. 
The horizon of Rhynchonella griesbachi not having been previously 
recognised in Spiti, a careful search was made during the last field 
season, with the result that it was found in the same position as in 
Kumaon, that is to say, below the nodular limestone. At the same 
time the true position of the horizon of Pseudomonotis himaica was 
also determined. While collecting from the horizon of Rhynchonella 
griesbachi, the present writer found, both in and above it, several 
pf^orly preserved fragments of ammo: ites, which appeared to resemble 
lower triassic species ; these were submitted to Dr. von Krafft, but they 
were in most cases too badly preserved to admit of determination. A 
' Denkscbrift. der k. Akad., Wien, LXII. 1895, p. 571. 
\ Pal. Indica, ser. XV, vol. Ill, pt. 2. 
F 2 ( 67 ) 
