The geographical distribution of animals, with a study of the relations ...

chap, xii.] THE ORIENTAL REGION. 341Kalophrynus, Ansonia, and Pscudobufo, are peculiar :while theOriental Mcgalophrys, Ixalus, Ehac&phorus, and Hylorana areabundant and characteristic.Fishes.—The fresh-water fishes of the Malay archipelagohave been so well collected and examined by the Dutchnaturalists, that they offer valuable indications of zoo-geographicalaffinity ; and they particularly well exhibit thesharply defined limits of the region, a large number of Orientaland even Ethiopian genera extending eastward as far as Javaand Borneo, but very rarely indeed sending a single speciesfurther east, to Celebes or the Moluccas. Thirteen families offresh-water fishes are found in the Indo-Malay sub-region. Ofthese the Scienidse and Symbranchidae have mostly a widerange in the tropics. Ophiocephalidse are exclusively Oriental,reaching Borneo and the Philippine islands. The Mastacembelidseare also Oriental, but one species is found as far as Ceram.Of the ISTandidse, 3 genera range over the whole region. TheLabyrinthici extend from Africa through the Oriental region toAmboyna. The single species constituting the family Luciocephalidaeisconfined to Borneo and the small islands of Bilitonand Banca. Of the extensive family Siluridse 17 genera areOriental and Malayan, and 11 are Malayan exclusively; andnot one of these appears to pass beyond the limits of the subregion.The Cyprinidse offer an equally striking example, 23genera ranging eastward to Java and Borneo and not onebeyond; 14 of these being exclusively Malayan. It must beremembered that this is not from any want of knowledge of thecountries farther east, as extensive collections have also beenmade in Celebes, the Moluccas, and Timor ; so that the facts ofdistribution of fresh-water fishes come, most unexpectedly, tofortify that division of the archipelago into two primaryregions, which was founded on a consideration of mammaliaand birds only.Insects.—Few countries in the world can present a richer andmore varied series of insects than the Indo-Malay islands, andwe can only here notice a few of their more striking peculiaritiesand more salient features.