Geographical Distribution 377 



I. THE ANTILLEAN SUB-RE(}ION. 



This consists of the West Indian Islands, to which many 

 forms of birds are restricted, the most noteworthy being 

 perhaps the Todies (Sub-Order Todi), of which the islands 

 of Jamaica, Cuba, Porto Rico, and St. Domingo each con- 

 tain a species. Several genera and species of Passerine 

 Birds are also peculiar to this Sub-Region. 



I. THE CENTR.AL AMERICAN SUB-REGION. 



This includes the whole of Central America from Mexico 

 southwards to the Isthmus of Panama, leaving out the 

 plateau of Central Mexico, which belongs to the Sonoran 

 Sub-Province of the Nearctic Region. Mr. Osbert Salvin 

 has pointed out that the Neotropical Avifauna reaches on 

 the eastern side almost to the Rio Grande, following the 

 line of the forest-country, so that Toucans, Motmots (p. 79), 

 Tinamous, and Curassows reach nearly to the above-named 

 river, and one species of Curassow, Ortalis vctula, actually 

 extends into Southern Texas. 



A. The Mexican Province. 



This extends as far as Costa Rica, where a certain 

 difference- in the Avifauna is found, and the birds of the 

 latter country have more affinity with those of Panama. 



B. The Isthmian Province. 



In Costa Rica and Panama there are several genera 

 which do not occur in the Mexican Province, and there is 

 a strong connection with the Ecuadorian Avifauna, several 

 species from which find their northern range in Panama. 



