| Quadrumana. 1. Simia morio. A small orang-utan with large incisor teeth. 2. Hylobates mulleri. 3. Nasalis larvatus. 4. Semnopithecus rubicundus. 5. ,, chrysomelas. 6. ,, frontatus. 7. ,, hosei. (Thomas.) Kini Balu. Carnivora. 8. Herpestes semitorquatus. 9. Felis badia. Ungulata. 10. Sus barbatus. Rodentia. 11. Pteromys phæomelas. 12. Sciurus jentinki. (Th.) Kini Balu. | 13. Sciurus whiteheadi. (Th.) Kini Balu. 14. ,, everetti. 15. Rheithrosciurus macrotis. 16. Hystrix crassispinis. 17. Trichys guentheri. 18. Mus infraluteus. (Th.) Kini Balu. 19. ,, alticola. (Th.) Kini Balu. Insectivora. 20. Tupaia splendidula. 21. ,, minor. 22. ,, dorsalis. 23. Dendrogale murina. Chiroptera. 24. Vesperugo stenopterus. 25. ,, doriæ 26. Cynopterus brachyotus. 27. ,, lucasii. 28. ,, spadiceus. 29. Hipposideros doriæ. |
Of the twenty-nine peculiar species here enumerated it is possible that a few may be found to be identical with those of Malacca or Sumatra; but there are also four peculiar genera which are less likely to be discovered elsewhere. These are Nasalis, the remarkable long-nosed monkey; Rheithrosciurus, a peculiar form of squirrel; and Trichys, a tailless porcupine. These peculiar forms do not, however, imply that the separation of the island from the continent is of very ancient date, for the country is so vast and
so much of the once connecting land is covered with water, that the amount of speciality is hardly, if at all, greater than occurs in many continental areas of equal extent and remoteness. This will be more evident if we consider that Borneo is as large as the Indo-Chinese Peninsula, or as the Indian Peninsula south of Bombay, and if either of these countries were separated from the continent by the submergence of the whole area north of them as far as the Himalayas, they would be found to contain quite as many peculiar genera and species as Borneo actually does now. A more decisive test of the lapse of time since the separation took place is to be found in the presence of a number of representative species closely allied to those of the surrounding countries, such as the tailed monkeys and the numerous squirrels. These relationships, however, are best seen among the birds, which have been more thoroughly collected and more carefully studied than the mammalia.
Birds.—About 580 species of birds are now known to inhabit Borneo, of which 420 species are land-birds.[[140]] One hundred and eight species are supposed to be peculiar to the island, and of these one half have been noted, either by Count Salvadori or Mr. Everett, as being either representative species of, or closely allied to birds inhabiting other islands or countries. The majority of these are, as might be expected, allied to species inhabiting the surrounding countries, especially Sumatra, the Malay Peninsula, or Java, a smaller number having their representative forms in the Philippine Islands or Celebes. But there is another group of eight species whose nearest allies are found in such remote lands as Ceylon, North India, Burma, or China. These last have been indicated in the following list by a double star (**) while those which are representative of forms found in the immediately surrounding area, and are in many cases very slightly differentiated from their allies, are indicated by a single star (*).
List of Birds which are supposed to be peculiar to Borneo.
Representative forms of the same character as those noted above are found in all extensive continental areas, but they are rarely so numerous. Thus, in Mr. Elwes' paper on the "Distribution of Asiatic Birds," he states that 12.5 per cent. of the land birds of Burmah and Tenasserim are peculiar species, whereas we find that in Borneo they are about 25 per cent., and the difference may fairly be imputed to the greater proportion of slightly modified representative species due to a period of complete isolation. Of peculiar genera, the Indo-Chinese Peninsula has one—Ampeliceps, a remarkable yellow-crowned starling, with bare pink-coloured orbits; while two others, Temnurus and Crypsirhina—singular birds allied to the jays—are found in no other part of the Asiatic continent though they occur in some of the Malay Islands. Borneo has seven peculiar genera of passeres,[[141]] as well as Hæmatortyx, a crested partridge; and Lobiophasis, a pheasant hardly distinct from Euplocamus; while two others, Pityriasis, an extraordinary bare-headed bird between a jay and a shrike, and Carpococcyx, a pheasant-like ground cuckoo formerly thought to be peculiar, are said to have been discovered also in Sumatra.
The insects and land-shells of Borneo and of the surrounding countries are too imperfectly known to enable us to arrive at any accurate results with regard to their distribution. They agree, however, with the birds and mammals in their general approximation to Malayan forms, but the number of peculiar species is perhaps larger.
The proportion here shown of less than one-fourth peculiar species of mammalia and fully one-fourth peculiar species of land-birds, teaches us that the possession of the power of flight affects but little the distribution of