fART ].] McViihoii; Notes of a Imr thonijh Hang rang and Spilt, 
57 
Tills, I tliiiik, can only be accounted for by the larger bones being, firstly, more 
likely to escape destruction, and secondly, being more likely to be obtained by col¬ 
lectors. We are not therefore, from the paucity of small bird-bones, to argue that 
the smaller birds were not fully represented in the Siivalik fauna, any more 
than in the case of the small mammals, of which the remains are likoAvise extreme¬ 
ly rare. Since bird.s, as a rule, are of far inferior size to mammals, it is only 
natural to expect that the discovered fossil bones of the former should only pre¬ 
sent a very small percentage of those of the latter. 
With regard to the Siwalik tarso-metatarsus stated by M. Milne-EdAvards 
to indicate a bird closely allied to the living Tropic birds {Phaeton), it seems 
incredible that a bird of that essentially oceanic genus could haA'e lived in tho 
land-locked Siwalik country. The difficulty may perhaps bo got over by calling 
in question the authenticity of the locality of the bone, of Avhioh there seems no 
certain history. 
Notes of a tour through Hangravg and Spiti, hg Colonel C. A. McMahon. 
Circumstances OA^er Avhich I had no control delay^ed my departure from 
Simla so long, that the time at my disposal Avas only sufficient to enable me to 
make road-side observations by the Avay'. I could only devote one halt to ex¬ 
plorations off the road. 
In my last paper (Rec. Gool. Surv., X, p. 204) I described the rocks of tho 
Upper Sutlej as far as Jangi, and I noAV proceed to describe the section from 
that place to Spiti, via the Ruhang and Hangrang passes. 
The dip of the schists and central gneiss betAveen Pangi and Jangi varies 
from north-east to ea.st-north-east. BetAveen these places, as described in my 
last paper, frequent intrusions of granite culminate in an eruption on a grand 
scale; the granite constituting the core of the Gongra ridge, and extending in a 
north-westerly direction from near tho confluence of the Todoong Gar river 
Avith tho Sutlej, to Lepi. AVhether it extends beyond Lepi I do not know. The 
rocks fringing this central granitic core, and forming the minor ridg'es of tho 
Gongra range, are mica schists. On leaving Jangi (elevation 8,850 feet)i the 
dip is at first flat, but as Lepi (elevation 8,880 feet) is neared, a Avest-south-wost 
dip is set up. Between Lepi and the top of the Ruhang pass (eloAution 14,354 
feet, T. S.) the dip A'aries from north-north-east to north-west. The rocks, Avhich 
at first are silicious and micaeeou.s schists, gradually get more and more slaty, 
and finally pass into unmitigated slates with a grey streak. 
Whether there is a gradual transition from metamorjihic ciystalline rocks 
to clay slates—the one gradually passing into the other—or Avhether the transition 
is merely apparent, I cannot positively state. It W'ould require, I think, a care¬ 
ful detailed survey of the ground to decide the que.stion definitely. It is impos- 
* The elevations given are generally those shown hy iny aneroid barometer; when the trigono¬ 
metrical survey elevations are given, tho lettin's T. S. are affixed. 
H 
