1917.] Chapman, Distribution of Bird-life in Colombia. 141 



northern ends of the Western and Central Andes. In the Central Andes the 

 Subtropical Zone of the western slope is prevented from coming in contact 

 with the same zone on the eastern slope by the Temperate Zone until the 

 northern end of the range is reached in Antioquia. In the Eastern Andes 

 the zones of eastern and western slopes doubtless also meet where decreasing 

 altitude near the northern end of the range permits them to cross the divide, 

 and Miller's work in the southern part of this range shows that the pass at 

 Andalucia (alt. 7000 ft.) is in the heart of the Subtropical Zone which here, 

 as in the greater part of the ^Yeste^n Andes, occupies both slopes and the 

 crest of the range. 



Notwithstanding these, chiefly terminal, connections it is evident that 

 the three branches of the Subtropical Zone in Colombia are sufficiently 

 isolated from one another to become centers of local, adaptive radiation. 

 The life of the Subtropical Zone as a whole, however, is remarkably uni- 

 form, more than half of its characteristic species being distributed throughout 

 its greater part. 



Thus of the 230 distinctively Subtropical Zone species found by us in 

 Colombia, 121 ar^ present either as unchanged or intergrading forms in 

 all three Andean ranges. The remaining 109 species may be distributionally 

 classified as follows: 



Peculiar to the Western Andes 31 species 

 " " Central " 9 " 



" " Eastern " 22 



Common to the Western and Central Andes ' 14 " 



" " " Eastern and Central Andes 2 33 



The facts expressed by this analysis appear to require the recognition 

 of at least two subdivisions of the Subtropical Zone of the Colombian Andes 

 which I suggest be known as: 



1. The West Andean Subtropical Fauna. 



2. The East Andean Subtropical Fauna. 



Before treating of these minor divisions of the Subtropical Zone it seems 

 desirable to give a list of the species we collected in it. 



Birds of the Subtropical Zone. 



Family -TiTiamidcB Family Cracidce 



Tinamus tao Penelope cristata 

 Nothocercus bonapartei " perspicax 



" intercedens {vide HeUmasr) Abmria aburri 



^ Chiefly the western slope. 

 2 Chiefly the eastern slope. 



