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Show 1893.] MAMMALS OF THE BORNEAN ISLANDS. 493 Palawan, is drawn immediately to the eastward of the islands of Cagayan Sulu and Sibutu,-whence it is continued through the Macassar Straits south of the Paternoster, Lauriot (Laset Ketjil), and Solombo islets, and in a north-westerly direction through the Karimata Strait back to the island of St. Julian. In attempting thus to define the area within which the neighbouring smaller islands may be regarded as being affiliated zoologically to Borneo, there exists no guide in many cases beyond their greater proximity to the latter island than to the other large masses of land by which they are more or less closely environed, supplemented by the evidence (often very imperfect) afforded by the soundings shown on our Admiralty charts. The limits adopted above must therefore be looked upon as being in some degree approximate. Nevertheless, as there are not any islands of considerable size of which the fauna is wholly unknown bordering upon the line of delimitation, it is not probable that material extensions or contractions of the boundary here assumed for the Bornean group as a wdiole will be necessitated by the result of future field-work. Turning to the accompanying list, it m ay be remarked that no family of Mammals is peculiar to the group and that only three genera are so, viz. Nascdis, Trichys, and Rhithrosciurus, which, so far as we know at present, are all confined exclusively to the island of Borneo itself. Peculiar species, however, are fairly numerous, and they are indicated in the list by the prefix of a single or double asterisk in accordance with their being confined to Borneo or to the Palawan Sub-group respectively. Although the general facies of the mammalian fauna of the Sub-group is clearly Bornean, it is to be noted that no species appears to be peculiar to the group as a whole, a fact which suggests the inference that, closely connected as Borneo has undoubtedly been with Balabac and Palawan, and isolated as they have been together from the mainland of Asia, there has also been much isolation of Borneo and Palawan inter se. A few of the species enumerated have been no doubt introduced by man. Such are the C o m m o n Mouse and the Black and Brown Rat, with the Buffalo; and it seems probable that the Javan Sambur (Cervus hippelaphus) and the Elephant owe their presence to the same agency. A few other species which have been credited to Borneo will be found to have been omitted below. Thus Hylobates concolor, Harlan, is almost certainly identical with H. muelleri, Martin. Macacus maurus, F. Cuv., long believed to inhabit Borneo, has been shown \ to be restricted to the southern peninsula of Celebes and to the neighbouring island of Bouton. There is a stuffed specimen of Canis aureus, Linn., in the Leyden Museum which is labelled as having been collected by Diard in Borneo, but it is more than doubtful whether the locality is correct2. The Javan Rhinoceros (R. sondaicus) has been supposed to exist in Borneo, but my inquiries on the subject have failed to elicit any reliable evidence 1 Weher, Zool. Ergebn. Niederl. Ost-Ind., Leiden, 1890. p. 103. 2 Blanford, Faun, Brit. India, Mammalia, i. p. 141. |