SWIFT. INSESSORES. CYPSELUS. 129 



the wing. The shortness of the tarsi, and the great length 

 of the wings, render the Swift unable to rise from an even 

 surface ; it is therefore (as if conscious of such inability) 

 never seen to alight on the ground. It can, however, fix 

 itself with ease against the perpendicular face of walls or 

 rocks, by means of its strong toes and hooked claws, which 

 are disposed in a different manner from those of the prece- 

 ding genus. 



It is found throughout the Old Continent, but has not 

 been met with in America. According to TEMMINCK, it 

 does not migrate beyond the Tropics. 



PLATE 42. Fig. 4. Natural size. 



Bill black. Throat smoke-grey. The rest of the plumage General 

 greenish-black, with reflections ; the feathers close in 

 texture, and firmly pressed together. Tarsi covered 

 with small feathers. Irides brown. 



FAMILY III. CAPRIMULGIDJE. 



THE members of this family (which forms the second 

 typical division of the tribe) are birds of nocturnal or cre- 

 puscular habits, clothed with a plumage, both in texture and 

 appearance, very similar to that of the Owls, with which rap- 

 torial group they are brought into close connection by means 

 of the genus Podargus, where the bill acquires great strength 

 and convexity, and the space around the eyes and base of 

 the bill becomes furnished with radiating hairy feathers. In 

 the typical genera the external or horny part of the bill 

 (as in the Hirundinidce) is very small and slender, the gape 

 very large, and its margin beset at regular distances with 

 long stiff' bristles, moveable when requisite, and, by their 

 converging power, of use in securing and detaining their 

 prey. The legs are short and weak, but there is a full de- 

 velopment of wings and tail, and consequently a correspond- 



VOL. I. I 



