CHAP. Ill ZOOLOGICAL REGIONS 53 



this region is equally peculiar, but we need not refer to 

 these here, our only object now being to establish by a 

 sufficient number of well-known and easily remembered 

 examples, the distinctness of each region from all others, 

 and its unity as a whole. The former has now been 

 sufficiently demonstrated, but it may be well to say a few 

 words as to the latter point. 



The only outlying portions of the region about which 

 there can be any doubt are — Central America, or that 

 part of the region north of the Isthmus of Panama, the 

 Antilles or West Indian Islands, and the temperate por- 

 tion of South America including Chili and Patagonia. 



In Central America, and especially in Mexico, we have 

 an intermixture of South American and North American 

 animals, but the former undoubtedly predominate, and a 

 large jDroportion of the peculiar Neotropical groups extend 

 as far as Costa Rica, Even in Guatemala and Mexico we 

 have howling and spider-monkeys, coati-mundis, tapirs, 

 and armadillos ; while chatterers, manakins, ant-thrushes, 

 and other peculiarly Neotropical groups of birds are abund- 

 ant. There is therefore no doubt as to Mexico forming 

 part of this region, although it is comparatively poor, and 

 exhibits the intermingling of temperate and tropical forms. 

 The West Indies are less clearly Neotropical, their 

 poverty in mammals as well as in "most other groups being 

 extreme, while great numbers of North American birds 

 migrate there in winter. The resident birds, however, 

 comprise trogons, sugar-birds, chatterers, with many hum- 

 ming-birds and parrots, representing eighteen peculiar 

 Neotropical genera ; a fact which decides the region to 

 which the islands belong. 



South temperate America is also very poor as compared 

 with the tropical parts of the region, and its insects contain 

 a considerable proportion of north temperate forms. But 

 it contains armadillos, cavies and opossums ; and its birds 

 all belong to American groups, though, owing to the 

 inferior climate and deficiency of forests, a number of the 

 families of birds peculiar to tropical America are wanting. 

 Thus there are no manakins, chatterers, toucans, trogons, 

 or motmots; but there are abundance of hang-nests, 

 tyrant-birds, ant-thrushes, tree-creepers, and a fair pro- 



