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as far as the highlands of Abyssinia. But representatives of all of them are found in the Palæarctic Region.
Among the Rodents of the Oriental Region the Squirrels are especially numerous, there being upwards of fifty species found within its limits, nearly all of which are arboreal in their habits.
Although there are no families of Carnivores peculiar to the Region, there is a considerable number of genera of Civets (Viverridx) not found elsewhere, such as the Paradoxures (Paradoxurus) the Binturong (Arctictis) (Fig. 26, p. 128), and the genera Prionodon, Arctogale, and Hemigale. The Bears (Ursidae), too, which are quite unknown in Africa, are characteristic members of the Oriental Mammal-fauna.
Among the Insectivores we find two peculiar families. One of these has been formed for the reception of Galeopithecus, the so-called Kaguan, an animal of about the size of a small cat, with thin flaps of skin between the fore and hind limbs and tail, which enable it to make flying leaps from tree to tree (see Fig. 27, p. 130). The other family (Tupaiidæ) contains two genera. One of these, Tupaia, with at least twelve species, is an abnormal Shrew with a curious external resemblance to the Squirrels, with which, however, it has no real connection. The other, Ptilocercus, is distinguished from Tupaia by its peculiar tail, which is provided at the end with a bilateral fringe of long hairs. Both these families are confined to the Malayan portion of the Oriental Region.
Bats are numerous in the Oriental Region, and many of the genera extend eastwards into the Austro-Malayan islands. Only four genera, each with a single species, are peculiar.
Finally, among the Primates there are three genera of Lemurs. Two of these (Nycticebus and Loris) are peculiar,
but belong to the family Lemuridæ, and have their nearest allies in Africa. The third (Tarsius), which forms a family
of itself, is practically confined to the Region, although it has slightly overstepped its boundaries, being said to occur in one of the smaller Austro-Malayan islands between Sumba and Timor. Besides the Lemurs, six genera of true Monkeys are found in the Oriental Region. Three of these, the Proboscis Monkey of Borneo (Nasalis), the Gibbons (Hylobates), and the Orangs of Sumatra and Borneo (Simia), are strictly endemic; while the other three, although highly characteristic of this Region, have extended their range slightly across its frontiers.
Summarizing these results, we shall find that the Oriental Region contains only two truly endemic and one quasi-endemic families out of a total of thirty-six which occur within its limits. These are the Galeopithecidæ (Flying Lemurs), Tupaiida (Tree shrews), and Tarsiida (Tarsiers).
The total number of genera found in the Region is 113, out of which 38 are peculiar; 11 extend their ranges slightly beyond the limits of the Region, and 64 are widely spread. On reducing these figures to an average, it will be found that the Oriental Region contains about 38 per cent. of peculiar genera, or, if the quasi-endemic genera be added, about 45 per cent. In either case, this shows a much lower percentage of peculiarities than has been shown to exist in the three Regions previously considered.
SECTION III.—SUBDIVISION OF THE ORIENTAL REGION
The Oriental Region, as regards its mammals, may be most conveniently divided into four Sub-regions (see Map, Plate V., p. 152). These are:
1. The Indian Sub-region.—This comprises the whole of India proper from the Suliman range and the lower slopes of the Himalayas to Cape Comorin. A line drawn northwards from Calcutta to the Himalayas, forms the approximate eastern boundary between this Sub-region and the next. There should also be included in this Sub-region the island of Ceylon, and probably the narrow, low-lying strip of desert country between the Persian Gulf and the central plateau of Persia.
2. The Burmo-Chinese Sub-region.—This Sub-region includes the portion of Sikkim below 10,000 feet, Assam, China south of the northern water-parting of the Yang-tzeKiang, the islands of Formosa and Hainan, and all the countries of the Indo-Chinese peninsula (Cochin China, Siam, and Burma), its southern land-boundary being approximately a line running to the north of the Malay peninsula from Tavoy on the west, to Bangkok on the east, at about 15° N. lat.
3. The Malayan Sub-region.— The Malay peninsula, together with the great islands of the East Indian archipelago, Sumatra, Java, Borneo, and the Philippines, forms a third division, which may be called the Malayan Sub-region.
4. The Celebesian Sub-region, containing only the island of Celebes.
This subdivision of the Oriental Region differs from that adopted by Wallace in two important points :
(a) In the combination of Wallace's Indian and Ceylonese Sub-regions into one—the Indian Sub-region.
(6) In the transference of Celebes from the Australian to the Oriental Region, and the formation of a new Subregion for its reception.
The reasons for these changes may be here briefly considered. First, as regards Ceylon, there are nineteen
genera of mammals found in the Indian Sub-region, which do not extend their range further eastwards into the BurmoChinese Sub-region. Of these, thirteen are to be met with also in the Palæarctic and Ethiopian Regions, leaving only six confined to the Indian Sub-region. These six are—
(1) Tetraceros (Four-horned Antelope).
Of these, Loris alone is characteristic of Southern India and Ceylon (the Ceylonese Sub-region of Wallace). Melursus is found in Ceylon, but occurs also all over the peninsula of India from the Himalayas southwards. Platacanthomys inhabits the western Ghats and the Animali hills of Southern India alone, and not Ceylon; the remaining three genera are distributed over the whole of the Indian peninsula, but do not reach Ceylon.
There is, therefore, only one genus of mammals confined to the Ceylonese Sub-region of Wallace, and this hardly seems to afford an adequate reason for separating it from the Indian Sub-region proper. The chief ground for so doing, according to Mr. Wallace, is the existence there of a peculiar family of snakes—the Uropeltids, or Rough-tails, which are entirely confined to Wallace's Ceylonese Sub-region. Examples of these reptiles, however, have been recorded in India as far north as Ganjam, in 20° N. lat., and it seems probable that they may eventually be found all over the peninsula south of the great plains of the Indus and the Ganges.
Secondly, as regards Celebes, this island certainly