constitute a family peculiar to the region. Two orders-Primates and Bruta-highly characteristic of the Central American and Brazilian regions, are wholly absent. There are also no Ungulates, very few Carnivores, and very few Rodents; the latter, however, are of mostly peculiar species, as are many of the Bats. The single Insectivore is of a remarkable type, which finds its nearest ally in the remote island of Madagascar, the ordinary Insectivores of the neighboring Central American and North American Regions being wholly unrepresented.

Brazilian Region.-Of about ninety commonly recognized genera, a little less than one-third may be considered as either wholly or mainly restricted to the region; a little less than another third range to the northward over much of the Central American Region, and may be considered as characteristic of the American Tropical Realm at large rather than of the Brazilian Region. About one-tenth of the remaining genera occur also over a large part of the Central American Region, while the remainder are divided about equally between tropicopolitan and cosmopolitan genera, and those that range southward over the South American Temperate Realm. One genus is also East Indian and another African, while quite a number range throughout the temperate and tropical parts of both Americas, and a few others over Temperate South America.

It is eminently characterized by its dozen genera of Monkeys, which, excepting a few that range into the Central American Region, are restricted wholly to this region; also by twelve to fifteen genera of Bats, which are scarcely found beyond its borders; nearly as many genera of Rodents, and quite a number of peculiar genera of other groups. Negatively it is characterized by the absence of Insectivores, the great bulk of the northern types of Carnivores, Ungulates, and Rodents. Its sole affinity with the life of the North Temperate Realm consists in the presence of a few such wide-ranging (cosmopolitan) genera as Felis, Sciurus, Lepus, Vespertilio, etc., and two other genera (Procyon and Didelphys) that range far into North America.

It is susceptible of division into several provinces, upon the detailed

* Dr. Coues gives Hesperomys (Oryzomys) palustris as Jamaican.—Mon. N. Am. Rod., 116, foot-note.

1

consideration of which it is not proposed at present to enter. These are the Upper Amazonian Province, embracing the region drained by the Upper Amazon and its principal tributaries (Western Brazil and those portions of Peru and Bolivia east of the Andes); the Lower Amazonian Province, embracing the Lower Amazonian and Orinoco Basins; and the Southeast Brazilian Province, embracing Southeastern Brazil and Paraguay. They are characterized by the occurrence of numerous peculiar species rather than by peculiar genera. The genus Lagothrix appears to be confined, however, to the Upper Amazonian Province, Chrysothrix to the Lower Amazonian, and Brachyteles to the Southeast Brazilian, where occur also Icticyon, Thous, Lycolepex, etc., not found in the other regions, but ranging thence southward to Patagonia.

Summary.

Whole number of genera

Mainly restricted to the region.

Of general distribution throughout the American Tropical Realm...
Occurring also over much of the South American Temperate Realm..
Occurring also in the warmer parts of the North Temperate Region....
Tropicopolitan
Cosmopolitan

90

31

41

9

6

3

6

IV. SOUTH AMERICAN TEMPERATE REALM. What is here termed the South Americau Temperate Realm embraces all that portion of the South American continent and adjacent islands not included in the American Tropical Realm as already defined. It coincides very nearly with Mr. Wallace's "South Temperate America or Chilian Subregion ".* Its northern limit on the Atlantic coast is near the thirtieth parallel. On leaving the Atlantic coast, the northern boundary passes obliquely northwestward, rising in the region of the Chaco Desert, to, or possibly a little beyond, the Tropic of Capricorn. Again descending to about the twenty-fifth parallel, it turns abruptly northward and eastward, along the eastern border of the Andean chain, nearly to the fifth degree of south latitude, near which point it strikes the Pacific coast. It thus embraces a large part of the great Andean plateau, with the neighboring coast region to the westward, nearly all the La Plata plains, and the region thence southward to Tierra del Fuego, which belongs also to this region.

As contrasted with the Tropical Realm to the northward, it is characterized, in respect to mammals, by the absence of all Quadrumana and the paucity of Edentates and Marsupials, there being neither Sloths nor Anteaters, while only two or three species of Opossums barely extend over its borders; the absence of all genera of Leaf-nosed Bats, and of not less than a dozen important genera of Rodents, the Coatis, the Kinkajou, the Tapirs, and many other genera characteristic of the American tropics. As noted by Mr. Wallace, it is further characterized by the possession of the entire family of the Chinchillida, the genera Auchenia, Habrocomus, Spalacopus, Actodon, Ctenomys, Dolichotis, Myopotamus, Chlamadophorus, to which may be added the marine genera Otaria, Arctocephalus, Morunga, Lobodon, and Stenorhynchus, very few of which range beyond the northern border of this region. The Spectacled Bear is also confined to it, and here are also most largely developed the Murine genera Calomys, Acodon, and Reithrodon.

Although one of the smallest of the primary regions, it is apparently divisible into two more or less well-marked provinces, which may be Geog. Distr. Animals, vol. ii, p. 36, and map of the "Neotropical Region”.

Among the genera of the Brazilian Region here unrepresented are, aside from the Quadrumana, Cercoleptes, Nasua, Tapirus, Bradypus, Chalopus, Myrmecophaga, Tamandua, Cyclothurus, Phyllostoma, Glossophaga, Arctibeus, Dysopes (and other genera of Chi roptera), Hydrochorus, Cercomys, Dactylomys, Loncheres, Echimys, Cœlogenys, Dasyprocta, Chatomys, Cercolabes, Lepus, Sciurus, Habrothrix, Oxymycterus, Holochilus, etc., = 27+.

respectively termed the Andean and Pampean. The Andean Prov ince is principally characterized by the presence of Ursus (Tremarctus) ornatus, the genera Pudu, Furcifer, Tolypeutes, Chlamydophorus, Chin chilla, Lagidium, Spalacopus, Habrocomus, and Octodon. Auchenia and several genera of Rodents range from the Andean Province southward over the plains of Patagonia to Tierra del Fuego. The Pata gonian plains share largely in the general facies of the Andean fauna. A few genera only are restricted to the Pampean Province, these being mainly Ctenomys, Lagostomus, and Dolichotis. The differences between these two provinces relate mainly to species rather than to genera. The Pampean Province is much the smaller, embracing only the compara tively level pampa district bordering the La Plata and Lower Parana Rivers. So little is definitely known respecting the range of the mam mals of this general region that it is scarcely practicable to attempt at present a definition of the boundaries between the Pampean and Andean divisions.

The relation of the South Temperate Americau to the Tropical Amer ican Realm is of course far closer than to any other, there being as usual a gradual transition between the two along their line of junctior, through the extension of a few forms characteristic of the one for a short distance into the other, just as has been observed to be the case between the North Temperate and Tropical American Realms. It has, however, nothing in common with the North Temperate American Realm beyond the presence of a few cosmopolite types that extend across the intermediate Tropical Realm. So far as land mammals are concerned, it has no genera common to the South Temperate portions of the Old World, except a few that are almost cosmopolite. The case is different, however, with the marine species. Of the half dozen or more genera of Pinnipeds (the only marine forms we are here called upon to consider), none are peculiar to the shores of Temperate South America but are common to South Temperate and Antarctic shores generally. None of them, however, occur north of the tropics,* and it is hence only through these that there is any closer affinity between the mammalian life of this region and the South Temperate Zone gen erally than between it and that of north-temperate latitudes.

Of the thirty-four land genera below enumerated as occurring in the South American Temperate Realm, rather more than one-half (eighteen) are nearly or wholly confined to it. Most of the remainder extend far to the northward into Tropical America, and others reach North America, while five are almost cosmopolitan.

* Otaria alone reaches the Galapagos, which, although situated under the equator, are still within the influence of the cold Peruvian current, and appear to constitute an outlying element of the South American Temperate Realm.

The Indo-African Realm consists mainly of Intertropical Africa and Intertropical Asia, to which it seems proper to add Extratropical South Africa. The small portion of Africa south of the Southern Tropic lies wholly within the warm-temperate zone. Its small extent and broad connection with Tropical Africa render its separation as a distinct realm (as I at one time rather hastily considered it) almost inadmissible, since it is especially open to the influence of the great intertropical African fauna, as is shown by the extension of many tropical forms down to within a few degrees of its southern extremity. The area really possessing a temperate climate is restricted to its extreme southern border, where alone appear the few generic and family types that do not have a very general range over the tropical portions of the continent. This area is many times smaller than the temperate portion of South America, but, though so small, has quite a number of peculiar genera, which impart to it quite distinctive features. It yet seems better to regard it as an appendage of the great Indo-African Realm rather than as a distinct primary region. Madagascar, with the Mascarene Islands, on the other hand, while perhaps possessing a closer affinity with Africa than with any other continental region, has yet a fauna made up so largely of peculiar types that it seems more in accordance with the facts of distribution to regard it as a separate primary region.

The Indo-African Realm, as thus restricted, forms a highly natural division. Although its two principal areas are quite widely separated, being in fact geographically almost wholly disassociated, they possess a wonderful degree of similarity. Of the fifty commonly recognized families of mammalia occurring within its limits, three-fifths are distributed throughout almost its whole extent. Of the remainder, onehalf are confined to Africa, and one is African and American, leaving only nine in India that are unrepresented in Africa; three only of these latter are, however, peculiar to the Indian Region; all extend beyond it to the northward, five of them even occurring over the greater part of