364 

 PICA RUB. 



CYPSELIDiE. 



CYPSELID.F.. 



Cypselus apus (Linnaeus*). 

 THE SWIFT. 

 Cypselus apus. 



Cypselus, IUigerf. — Bill very short, wide, triangular at its base and depressed ; 

 culmen and commissure much decurved ; gape extending beyond the eyes. Nos- 

 trils longitudinal, the edges raised and furnished with small feathers. Wings, 

 with ten curved primaries, very long and pointed, the first a little shorter than 

 the second, but longer than the third. Tail, of ten feathers, somewhat deeply 

 forked. Tarsi very short, feathered in front ; toes four, all ordinarily directed 

 forwards, the middle and outer with three phalanges only ; claws short, large and 

 much curved. 



The characters which distinguish the Swifts from the 

 Swallows are even on a slight examination so well marked 

 and so decisive that it is curious their important hearing on 



* II ir undo apus, Liiunius, Syst. Nat. Ed. 12, i. p. 344 (1766). 

 t Prodr. Syst. Mamm. et Av. p. 229 (1811 \ 



