178 THE GEOGRAPHY OF MAMMALS 



is met with. Eastward of Sikkiin, however, as has already- 

 been shown, it is very difficult to draw a definite line, 

 chiefly in consequence of our defective knowledge ; but the 

 boundary already adopted in the case of the Oriental 

 Region seems, on the whole, to be a suitable one — namely, 

 that of the northern water-parting of the Yang-tse- Kiang 

 — thus leaving Moupin, and the district of Eastern Tibet 

 explored by the French missionary, Pere David, within 

 the confines of the Palsearctic Region. 



There are only two important groups of islands con- 

 nected with this Region ; these are the British Islands in the 

 West, and the Japanese Islands in the East. The faunas 

 of both these insular groups are of the true " continental- 

 island" type, and differ very slightly from that of the 

 neighbouring mainland. This is more especially the case 

 with the British Isles, where we find among the Mammals 

 no peculiarities worthy of mention, with the exception, 

 perhaps, of a recently discriminated stoat (Mustela hiber- 

 nica), said to occur only in Ireland. 



Section II. — General View of the Mammal-fauna 

 of the Palgearctic Region 



The Palsearctic Region, although covering a larger area 

 than any of the other Regions, comes out only fourth as re- 

 gards the number, both of species and of genera, of mammals 

 represented in it, being surpassed in this respect by the 

 Neotropical, Ethiopian, and Oriental Regions. The total 

 number of such genera is one hundred and three, out of 

 which twenty-five are absolutely confined within its limits, 

 while four others are highly characteristic of it, though they 

 just pass over its frontiers. The remainder, seventy-four 



