THE JURASSIC SYSTEM. 3^ 
from Tiina to Lhasa. The whole of the intervening area appears to 
be covered by slate, quartzite (rarely shale and sandstone) and 
limestone, thrown into an endless succession of complicated folds 
and pierced by dykes of basic igneous rock and intrusive masses 
of granite. The consequent destruction of most of the fossils 
adds to the difficulty of classifying the series, but on account of ti e 
persistence ol the iithological types and the occasional presence of 
Jurassic fossils, the whole series is referred to that system. 
The localities at which fossils were found are — 
1. 2^ miles north of Dochen. 
2. Tsalu. 
3. Hills east of Mangtsa. 
4. Khangnia. 
5. Hill east of Gyantse. 
6. Gorchi and Salagang. 
1. The first of these localities is at the top of a pass leading from 
Dochen to grazing-grounds between that village 
Dochen. 
and Kala Tso. The fossils occur m a narrow 
calcareous band in dark shales and consist of Gryphasa sp. very badly 
preserved. 
2. An impression of an ammonite was found in the shale at 
Tsalu by Mr. L. Truninger, CLE., but was not 
Tsalu. .-^ , ^ 
determmable. 
3. On the hills to the east of Mangtsa, a few poorly preserved 
brachiopods were collected from shaly beds by 
Mangtsa. Captain H. M. Cowie, R.E They include 
species of Spirijerina sp. and the impressions of a brachiopod 
externally resembling the liassic species Terebratula [Megerlea) 
Perrieri Desl. 
4. On the left bank of the river opposite the village of Khangma 
there is a cliff section of intensely folded shale 
Khangma. limestone. At some little distance from the 
river bank the base of the section is formed by a white crinoid 
limestone, composed almost entirely of stems of crinoids : above this 
( 158 ) 
