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

346 ZOOLOGICAL GEOGRAPHY. [part hi.The foregoing list, although small, contains an assemblage ofspecies which are wholly Oriental in character, and several ofwhich {Tardus, Galeopithecus, Tupaia) are characteristic andhighly peculiar Malayan forms. At the same time these islandsare completely separated from the rest of Malaya by the totalabsence of Semnopithecus, Hylobates, Fclis,Hclarctos, Rhinoceros,Manis, and other groups constantly found in the great Indo-Malay islands and peninsula of Malacca. We find apparentlytwo sets of animals : a more ancient series, represented by thedeer, Galeopithecus, and squirrel, in which the species are distinctfrom any others ; and a more recent series, represented byMacacus cynomolgus, and Viverra tangalunga, identical withcommon Malayan animals. The former indicate the earliestperiod when these volcanic islands were connected with somepart of the Malayan sub-region, and they show that this wasnot geologically remote, since no peculiar generic types havebeen preserved or differentiated. The latter may indicate eitherthe termination of the period of union, or merely the effects ofintroduction by man. The reason why a larger number ofmammalian forms were not introduced and established, wasprobably because the union was effectedonly with some smallislands, and from these communicated to other parts of thearchipelago ; or it may well be that later subsidences extinguishedsome of the forms that had established themselves.Birds of the Philippine Islands.— These have been carefullyinvestigated by Viscount Walden, in a paper read before theZoological Society of London in 1873, and we are thus furnishedwith ample information on the relations of this importantportion of the fauna.The total number of birds known to inhabit the Philippinesis 219, of which 106 are peculiar. If, however, following ourusual plan, we take only the land-birds, we find the numbersto be 159 species, of which 100 are peculiar ;an unusually largeproportion for a group of islands so comparatively near tovarious parts of the Oriental and Australian regions. Thefamilies of birds which are more especially characteristic of theIndo-Malay sub-region are about 28 in number, and examples