The assemblage of birds of the Indian region is one of the richest and most varied in the world, being surpassed only by that of tropical America. Nearly every order, except that of the Struthiones or ostriches, is well represented, and there are many peculiar genera not found elsewhere, such as _Buceros_, _Harpactes_, _Lophophorus_, _Euplocamus_, _Pajo_ and _Ceriornis_. The _Phasianidae_ (exclusive of true _Phasianus_) are highly characteristic ot this region, as are likewise certain genera of barbets (_Megalaema_), parrots (_Palaeornis_), and crows (_Dendrocitta_, _Urocissa_ and _Cissa_). The family _Eurylaemidae_ is entirely confined to this part of Asia.
The Ethiopian fauna plays but a subordinate part in Asia, intruding only into the south-western corner, and occupying the desert districts of Arabia and Syria, although some of the characteristic species reach still farther into Persia and Sind, and even into western India. The lion and the hunting leopard, which may be considered as in this epoch at least, Ethiopian types extend thus far, besides various species of jerboa and other desert-loving forms.
In the birds, the Ethiopian type is shown by the prevalence of larks and stone chats, and by the complete absence of the many peculiar genera of the Indian region.
The occurrence of mammals of the Marsupial order in the Molucca Islands and Celebes, while none have been found in the adjacent islands of Java and Borneo, lying on the west of Wallace's line, or in the Indian region, shows that the margin of the Australian region has here been reached. The same conclusion is indicated by the absence from the Moluccas and Celebes of various other Mammals, Quadrumana, Carnivora, Insectivora and Ruminants, which abound in the western part of the Archipelago. Deer do not extend into New Guinea, in which island the genus _Sus_ appears to have its eastern limit. A peculiar form of baboon, _Cynopithecus_, and the singular ruminant, _Anoa_, found in Celebes, seem to have no relation to Asiatic animals, and rather to be allied to those in Africa.
The birds of these islands present similar peculiarities. Those of the Indian region abruptly disappear at, and many Australian forms reach but do not pass, the line above spoken of. Species of birds akin to those of Africa also occur in Celebes.