BRITISH BIRDS. 



365 



to the greater coverts, is whitish ; the under coverts 

 of the wing are partly brown and partly bright 

 ferruginous; the legs are long, and bare above 

 the knee; toes brown, the claws slightly bent. 

 These birds are said to inhabit Germany, parti- 

 cularly on the borders of the Rhine, are some- 

 times seen in France, but are most plentiful in the 

 deserts towards the Caspian Sea, frequenting the 

 dry plains in great flocks. They are also common 

 throughout the deserts of Independent Tartary, as 

 far as the rivers Kamyschlossca and Irtish. They 

 make their nest in holes, like the Sand Martin, 

 in the sandy banks of rivers, and lay six or seven 



