96 



ELEMENTS OF OBNITHOLOBT. 



represents a group of Swallows and Martins which is spread 

 over the whole world, and contains about eighty-two species. 

 Of these the Comtnoa Swallow (Sirundo rustica) may answer 

 as our example. 



Swifts greatly resemble Swallows in general appearance and 

 in their mode of flight, though this is much more power- 

 ful. Nevertheless, as we shall see, they are reaUy very distinct 

 from them. They number about eighty-six different kinds, 

 which range through the warm and temperate regions of the 



Fig. 100. 



The Common Roller {Coradas garrula). 



globe. The Common Swift {Cypselus apus) stays with us little 

 more than three months, quitting our shores for the South 

 about the middle of August. 



Extremely contrasted with the Swift is that charming little, 

 bush-loving Bird the Wren (Anorthura troglodytes, fig. 102), the 

 lively shrill note of which may be heard all the year round. It 

 is an example of a numerous group of small, similar Birds num- 

 bering some hundred and thirty-four species, the great majority 

 of which are exclusively American. The G-olden-crested Wren 



