336 
ZOOLOGICAL GEOGRAPHY. 
[PART III. 
great islands were recently united to the continent, and that 
their separation took place by one general subsidence of the 
whole. It is more consonant w r ith what we know of such mat- 
ters, that the elevations and depressions were partial, varying 
in their points of action and often recurring; sometimes ex- 
tending one part of an island, sometimes another; now joining 
an island to the main land, now bringing two islands into closer 
proximity. There is reason to believe that sometimes an inter- 
vening island has sunk or receded and allowed others which it 
before separated to effect a partial union independently of it. 1 f 
we recognise the probability that such varied and often-renewed 
changes of level have occurred, we shall be better able to under- 
stand how certain anomalies of distribution in these islands may 
have been brought about. We will now endeavour to sketch the 
general features of the zoology of this interesting district, and 
then proceed to discuss some of the relations of the islands to 
each other. 
Mammalia. — We have seen that the Indo-Chinese sub-region 
possesses 13 species of mammalia in common w T ith the Indo- 
Malay sub-region, and 4 others peculiar to itself, besides one 
Ethiopian and several Oriental and Paltearctic forms of wide 
range. Of this latter class the Malay islands have compara- 
tively few, but they possess no less than 14 peculiar genera, viz- 
Simia, Siamanga , Tarsias, Galeopithecus, Hylomys , Ptilocerus, 
Gymnura, Cynogale , Hemigalea, Ardogale, Barangia, Mydaus, 
Hclardos, and Tapirus. The islands also possess tigers, deer, 
wild pigs, wild cattle, elephants, the scaly ant-eater, and most 
of the usual Oriental genera ; so that they are on the whole 
fully as rich as, if not richer than, any part of Asia ; a fact very 
unusual in island faunas, and very suggestive of their really 
continental nature. 
Plate VIII. Scene in Borneo ivith Charaderistic Malayan 
Quadrupeds. — The Malayan fauna is so rich and peculiar that 
we devote two plates to illustrate it. We have here a group of 
mammalia, such as might be seen together in the vast forests of 
Borneo. In the foreground we have the beautiful deer-like 
Chevrotain ( Tragulns javanicus). These are delicate little 
