C-XPSBLIDZE CYPSBLUS 21 



Genus I. CYPSELUS. 



Type. 

 Cypselus, Illig., Prodr. p. 229 (1811) C. apus. 



Tarsi feathered, outer and middle toes with three phalanges 

 only; all the toes directed forwards at equal intervals from one 

 another, though the first or inner one is reversible at will ; toes 

 unfeathered. Sexes alike. 



All the Swifts are birds of sombre plumage and of very powerful 

 flight. As a rule the nests are made against rocks or buildings and 

 built of feathers and other materials cemented together with saliva 

 not with mud. 



This genus is distributed over the whole of the world except in 

 the extreme north ; two species are found in South America but 

 the Swift of North America is referred to another genus. Shelley 

 recognises fifteen African species, several of which however, rest 

 on somewhat uncertain evidence. Five South African forms are 

 distinguished below. 



The names Apus and Micropus have been used for this genus, 

 as having priority to Cypselus ; but there seems to be excellently 

 valid reasons for ignoring both of them. 



Key of the Species. 



A. Larger, wing more than 6'0 ; back uniform. 



a. Abdomen and throat white separated by a 



, pectoral band , C. afiicanus, ip. 21. 



h. Brown below, only a throat patch white. 



a'. Smaller, wing 6'6 to 6'7 C ajjzts, p. 23. 



&'. Larger, wing 7'1 C. barbatus, p. 25. 



B. Smaller, wing less than 6'0 ; rump white. 



a. Tail deeply forked, difference between the 



inner and outer tail-feathers exceeding I'O C. caffer, p. 25. 



6. Tail nearly square, the difference between the 

 outer and inner tail-feathers hardly per- 

 ceptible C. affinis, p. 27. 



385. Cypselus africanus. WMte-belUed Sivi/t. 



Le Martinet a gorge blanche, Levaillant, Ois. d'Afr. v, p. 143, pi. 248 



(1806). 

 Cypselus alpinus africanus, Temm. Man. d'Orn. p. 270 [note] (1815). 

 Cypselus gutturaUs, Vieill. N. Diet. H. N. xix, p. 422 (1818) ; Tristram, 



P. Z. 8. 1867, p. 887 : Gurney, Ibis, 1868, p. 460 [Natal] ; Layard, 



