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a single foreign species, which feeds by night 

 in the manner of the Coprimulgidce ; and in 

 both groups completely insectivorous do we find 

 species at times feeding on fruits and berries, 

 the whole running into each other in a manner 

 beautifully graduated, at the same time each 

 being distinct and easily separated. The Swal- 

 lows range over the whole world, and are every 

 where migrating birds. They breed in the cre- 

 vices of rocks, or form curious nests of various 

 substances agglutinated together by their saliva, 

 and most delight in the vicinity of waters. The 

 colours of the plumage are steel blue, glossy 

 green, and brown, contrasted with white and 

 chestnut. In Britain we have two genera. The 

 first of which is 



HIRUNDO, Linn. Generic characters. Bill 

 small, very slightly bent, triangular, dilated at 

 the base, rictus very ample, without bristles ; 

 feet incessorial, but very slender ; tarsus 

 short ; wings long, pointed, first quill longest ; 

 tail forked, often much developed. 



Types. H. rustica, urbica, riparia. 



Note. Colours of the plumage glossy blue or 

 green, varied by chestnut and white ; migra- 

 tory, mostly gregarious. Cosmopolite. 



