president's addkess. 21 



V. THE DENDROG.^AN REALM. 



The South American or Neotropical Reabn extends from the N. , 

 near the northern boundaries of Mexico in the lowlands, and lower 

 down in the highlands, to the temperate regions of South America, 

 and its dependencies, for with it are also generally associated the 

 West Indian Islands. It has 30 families of mammals, 73 of birds, 

 35 of reptiles, 16 of amphibians, and 17 of fresh-water fishes. An 

 unusual proportion of these are peculiar to the region, or nearly so. 

 Among the mammals are the Cebidae, Mididse, Desmodidae, Dino- 

 myidae, Caviidse, Hydrochoeridas, Bradypodidae, Dasypodidse, 

 Tatusiidse, and Myrmecophagidse. Several of the families which 

 are shared in common with North America are also almost as 

 characteristic, the North American species being rather intruders 

 therein from the region under question than true autochthones. 

 Such are the Procyonidae, Bassaridid^, Saccomyidae, Cercolabidae, 

 Phyllostomidffi, and Didelphididce. Other families are peculiar in 

 their distribution : for example, of the Tapiridse, two well defined 

 genera and several species are found in South America, and the 

 only other representative is distant as far as the Indo-Malayan-Archi- 

 pelago. These are anomalies, however, that become readily explica- 

 ble when it is recalled that, in previous geological epochs, both of 

 the said families were extensively distributed over the northern 

 hemisphere, and consequently the Avidelf-separated living forms are 

 evidently simply surviving representatives of formerly widespread 

 types. Of birds, according to the views of Wallace and many or- 

 nithologists, 22 families are restricted to the region, and 7 others 

 are common and peculiar to it and the North American region. 

 The peculiar families of birds, according to Wallace, are the Csere- 

 bidae, or sugar-birds ; Phytotomidje, or plant-cutters ; Pipridse, or 

 manakins; Cotingids, or chatterers; Formicariidae, or ant-thrushes ; 

 Dendrocolaptidae, or tree-creepers; PteroptochidK ; Rhamphastidae, 

 or toucans ; Bucconidce, or puff-birds ; Galbulidse, or jacamars ; 

 Todids, or todies; Momotidae, or motmots ; Steatornithidae, the 

 guacharo or oil-bird ; Cracidae, or curassows ; Tinamidae, or tina- 



