THE NEOTROPICAL REGION 65 



Section III. — Subdivision of the Neotropical 

 Region 



The divisions of the Neotropical Region, as based on a 

 consideration of the class of birds (8), are six in number, 

 namely : — 



1. The Antillean Sub-region, containing the Greater 

 and Lesser Antilles, exclusive of Tobago and Trinidad. 



2. The Central- American Sub-region, containing all 

 that part of the whole region that is north of Panama. 



3. The Colombian Sub-region, containing Trinidad and 

 the slopes of the Andes, through Venezuela, Colombia, 

 Ecuador, and Peru, into Bolivia. 



4. The Amazonian Sub-region, embracing the whole 

 watershed of the Orinoco and Amazons up to the hills, 

 and including the highlands of Guiana. 



5. The South Brazilian Sub-region, containing the 

 wood region of South-East Brazil, Paraguay, and the 

 adjoining districts. 



6. The Patagonian Sub-region, containing Patagonia, 

 Southern Argentina, and Chili, and running up the west 

 coast of the continent to Guyaquil. 



This division, although perfectly good when the dis- 

 tribution of Birds is mainly relied upon, presents consider- 

 able difficulties in the case of Mammals, owing chiefly 

 to our ignorance of the limits of the distribution of 

 the greater number of the South American mammals, 

 especially of the smaller forms. There is, however, no 

 doubt that the Antilles or West Indies (excluding Trinidad 

 and the other islands off the coast of Venezuela, which are 

 connected with the mainland by quite shallow water) form 



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