CHAP. XII. ] THE ORIENTAL REGION. 359 
countries by arms of the sea rather wider than at present, 
might have left Banca isolated, as already referred to, with its 
proportion of the common fauna to be, in a few instances 
subsequently modified. 
Thus we are enabled to understand how the special relations 
of the species of these islands to each other may have been 
brought about. To account for their more deep-seated and 
general zoological features, we must go farther back. 
Probable Origin of the Malayan Fauna.—The typical Malayan 
fauna is essentially an equatorial one, and must have been 
elaborated in an extensive equatorial area. This ancient land 
almost certainly extended northward over the shallow sea as far 
as the island of Palawan, the Paracels shoals and even Hainan. 
To the east, it may at one time have included the Philippines 
and Celebes, but not the Moluccas. To the south it was limited 
by the deep sea beyond Java. It included all Sumatra and the 
Nicobar islands, and there is every reason to believe that it 
stretched out also to the west so as to include the central peak 
of Ceylon, the Maldive isles, and the Cocos islands west of 
Sumatra. We should then have an area as extensive as South 
America to 15° south latitude, and well calculated to develop 
that luxuriant fauna and flora which has since spread to the 
Himalayas. The submergence of the western half of this area 
(leaving only a fragment in Ceylon) would greatly diminish the 
number of animals and perhaps extinguish some peculiar types; 
but the remaining portion would still form a compact and exten- 
Sive district, twice as large as the peninsula of India, over the 
whole of which a uniform Malayan fauna would prevail. The 
first important change would be the separation of Celebes ; and 
5 his was probably effected by a great subsidence, forming the deep 
strait that now divides that island from Borneo. During the 
process Celebes itself was no doubt greatly submerged, leaving 
only a few islands in which were preserved that remnant of the 
ancient Malayan fauna that now constitutes one of its most 
striking and anomalous features. The Philippine area would 
next be separated, and perhaps be almost wholly submerged ; or 
