CHAI\ XVIII.] 



BIKDS. 



321 



Family 75.— TROCHILIDyE. (118 Genera, 390 Species.) 



The wonderfully varied and beautiful Humming-Birds are 

 confined to the American continent, where they range from 

 Sitka to Cape Horn, while the island of Juan Fernandez has two 

 peculiar species. Only 6 species, belonging to 3 genera, are 

 found in the Nearctic region, and most of these have extended 

 their range from the south. They are excessively abundant in 

 the forest-clad Andes from Mexico to Chili, some species extend- 

 ing up to the limits of perpetual snow ; but they diminish in 

 number and variety in the plains, however luxuriant the vege- 

 tation. In place of giving here the names and distribution of 

 the numerous genera into which they are now divided (which 

 will be found in the tables of the genera of the Neotropical 

 region), it may be more useful to present a summary of their 

 distribution in the sub-divisions of the American continent, 

 as follows : — 



Genera in each Sub-region 



Peculiar Genera 



Species in each Sub-region 



The island of Juan Fernandez has two species, and Masafuera, 

 an island beyond it, one ; the three forming a peculiar genus. 

 The island of Tres Marias, about 60 miles from the west coast 

 of Mexico, possesses a peculiar species of humming-bird, and 

 the Bahamas two species ; but none inhabit either the Falkland 

 Islands or the Galapagos. 



Like most groups which are very rich in species and in 

 generic forms, the humming-birds are generally very local, small 



