124 THE GEOGRAPHY OF MAMMALS 



Milne-Edwards (1). An examination of the list of the 

 mammals obtained by him in this district shows that the 

 fauna has a character intermediate between those of the 

 Oriental and Palcearctic Regions, besides containing a con- 

 siderable proportion of peculiar forms. As, however, most 

 of the Oriental genera extend even further north into the 

 Chinese province of Kansu, and some even cross into 

 Japan, countries which are otherwise well within the 

 Palsearctic Region, it will be most convenient to draw the 

 boundary of the Oriental Region to the south of Moupin. 

 Beyond this point again our knowledge of the distribution 

 of the mammals is very scanty, and though the northern 

 part of China appears to be distinctly Paleearctic, and the 

 southern Oriental in its affinity, there is, so far as we know, 

 a considerable admixture of forms all over this part of 

 Asia. Probably the most convenient boundary will be 

 found to be that adopted by Wallace — the northern edge 

 of the basin of the Yang-tze-Kiang. This is, no doubt, to 

 a great extent an artificial boundary, but such a fault is 

 unavoidable in the present instance, as there is here no 

 natural frontier to separate the two regions. In addition to 

 the south-eastern part of Asia, the Oriental Region includes 

 within its boundaries all the large and important islands 

 lying between that continent and the Australian Region. 

 The principal of these are the Chinese islands of Formosa 

 and Hainan, the large group of the Philippines, together 

 with Sumatra, Java, Borneo, and the adjacent islands up 

 to Wallace's Line. With the exception of Celebes, all these 

 islands are truly continental in character — that is to say, 

 are separated from the mainland by seas of less than 100 

 fathoms of depth. But Celebes is in some respects anoma- 

 lous, and will be considered in greater detail below. 



