146 



BIRDS OF THE BRITISH ISLES. 



white; orbits, whitish ; i rides, dark brown; upper mandible, 

 blackish, with a yellow base ; under mandible, yellow, with 

 a nearly black tip ; legs and feet, grey. 



Common Swift, 



THE Common Swift {Cypselus apus, Linnaeus) is a late 

 summer migrant to the British Isles, and is also a visitor 

 in summer to most parts of the Palearctic Region. It 

 spends the winter in Africa. The adult has the general 

 colour of the upper parts of plumage blackish-brown, with 

 bronze-like reflections ; chin and throat, dullish white ; 

 under parts, blackish-brown ; irides, dark brown ; bill and 

 feet, black; tarsi, covered with small feathers. Length, 



