t cosmopolitan wagtails are represented by a single species of
pipit.

We must also notice the preponderance of low or archaic types among the
animals of South America. Edentates, marsupials, and rodents form the
majority of the terrestrial mammalia; while such higher groups as the
carnivora and hoofed animals are exceedingly deficient. Among birds a low
type of Passeres, characterised by the absence of the singing muscles, is
excessively prevalent, the enormous groups of the ant-thrushes, tyrants,
tree-creepers, manakins, and chatterers belonging to it. The Picariae (a
lower group) also prevail to a far greater extent than in any other
regions, both in variety of forms and number of species; and the chief
representatives of the gallinaceous birds--the curassows and tinamous, are
believed to be allied, the former to the brush-turkeys of Australia, the
latter (very remotely) to the ostriches, two of the least developed types
of birds.

Whether, therefore, we consider its richness in peculiar forms of animal
life, its enormous variety of species, its numerous deficiencies as
compared with other parts of the world, or the prevalence of a low type of
organisation among its higher animals, the Neotropical region stands out as
undoubtedly the most remarkable of the great zoological divisions of the
earth.

In reptiles, amphibia, fresh-water fishes, and insects, {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 portion 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 proportion 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
ar