CYPSELUS. 291 



fortunate enough to receive a generic name which they were able to 

 retain, Illiger having rechristened the genus under the appellation of 

 Cypselus in his ' Prodromus systematis Mammalium et Avium/ p. 229. 

 He designated the Common Swift, the Hirundo apus of Linnaeus, as the 

 type. 



The true Swifts are characterized by having the tarsus feathered to the 

 base of the toes, which are all directed forward. The prevailing colour of 

 the Swifts is a brownish black, in some species variegated with white. 

 The similarity in the pattern of colour between the Swifts and the 

 Swallows is very remarkable ; in both families the sharply defined white 

 rump and dark pectoral band are occasionally met with. 



Sclater, in his monograph of the Cypselidae (Proc. Zool. Soc. 1865, 

 p. 593), enumerates fifteen species belonging to this genus, most of which 

 breed in the southern portions of the Paleearctic Region, and in the 

 Ethiopian and Oriental Regions. One species visits Australia in winter, 

 and four others are confined to the Neotropical Region. Two species only 

 occur in Europe, one of which is a regular summer visitor to the British 

 Islands, and the other is a rare accidental visitor. 



The Swifts live almost entirely on the wing, rarely perching in trees or 

 on the ground, and consequently frequent open country. They feed 

 exclusively on insects, and are therefore unable to remain in any locality 

 where the winter is at all severe. They breed in holes of various kinds, 

 the crevices of rocks, crannies in buildings, hollow trees, or the recesses 

 of palm-foliage. The nest is very slight ; the materials are made to adhere 

 to each other by the glutinous saliva of the birds. Their eggs are few in 

 number, elongated and blunt in shape, and unspotted dull white in 

 colour. 



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