LIFE-ZONES 629 



The southern of these two branch-Hnes cuts across the Tian Shan 

 system at the Tou-shui plateau between the Bogdo-ola and 

 Barkul ranges, and thence passes along the south of the Karlik 

 Tagh. The northern line runs south of the Baitik Mountains — 

 the almost isolated range between the Urungu River and Bogdo- 

 ola Mountains, and thence continues towards the east, either 

 embracing the Ati Bogdo in the neutral zone or leaving it to the 

 Altai-Mongolian subdivision. All to the north of these lines 

 is Altai and Mongolian, to the west and south is Tian Shan and 

 Chinese Turkestan fauna ; but the neutral zone, thus enclosed, 

 has a strange mixture of both fauna and flora. This area is com- 

 posed chiefly of the Barkul and Karlik Tagh ranges ; the most 

 easterly portion — the Ati Bogdo — must remain in an indefinite 

 position, for I have not been able to find sufficient details re- 

 garding its fauna to place it definitely within either. 



Of the fauna of the Karlik Tagh, the wild-sheep is of a species 

 peculiar to the Tian Shan {Ovis ammon karelini), and it is the 

 same with the wapiti, ibex, and roe-deer ; the snow-cock and 

 rock-partridge are also Central Asian varieties. The forests of 

 the Karlik Tagh are chiefly composed of the Tian Shan spruce 

 {Abies schrenkiana). But, on the other hand, the presence of 

 larch {Larix sibirica) gives the Karlik Tagh the aspect of Altai 

 scenery ; and the existence of certain mammals, — such as picas, 

 or tailless hares {Ochotona), and mole-rats [Ellobius) of species 

 closely allied to those of the Altai system — show the affinity that 

 the fauna of this region has to that of the Altai. The brown 

 partridge of this region is the Mongolian variety (Perdix daurica). 

 The Ati Bogdo Range, which lies about 180 miles to the 

 east of Karlik Tagh, — but is only connected with it by a succes- 

 sion of very low desert-hills, — probably belongs to the neutral 

 zone. Kozloff , the Russian explorer, reports finding larch forests, 

 wild-sheep, and roe-deer in this range ; and in all probability 

 these would prove to be of the same varieties as found on Karlik 

 Tagh. Altai fauna extends even farther to the east, for it 

 follows the long, low extension of spurs which run out in an 

 east-south-easterly direction from the main Altai to the neigh- 

 bourhood of Lat. 44° and Long. 401.° All these ranges contain 

 the wild-sheep and the snow-cock peculiar to the Altai and North- 



