72 CYPSELIN^. CYPSELUS. 



GENUS XVIII. CYPSELUS. SWIFT. 



Bill extremely short, depressed, broad at the base, nar- 

 rowed at the end ; upper mandible with its dorsal line con- 

 vex, the edges sharp, and incurved, the nasal sinuses very 

 large, the tip deflected ; lower mandible much smaller, and 

 slightly shorter, its angle very wide, the dorsal line very 

 short and convex, the edges involute, the tip narrow but 

 obtuse ; gape-line from beneath the hind part of the eyes, 

 arched. Upper mandible shallow, with a slightly promi- 

 nent central line ; palate flat ; tongue short, sagittate and 

 papillate at the base, bifid at the tip ; resophagus wide at 

 the commencement, then rather narrow ; proventriculus ob- 

 long ; stomach elliptical, with the muscular coat rather thin, 

 the cuticular lining thin, dense, longitudinally rugous ; in- 

 testine very short, rather narrow ; no coeca ; cloaca oblong. 

 Xostrils oblong, with an elevated margin. Eyes rather 

 large. Aperture of ear large, roundish. Body rather full, 

 elongated, flattened ; neck very short ; head broad. Feet 

 extremely short, strong ; tarsus extremely short, bare be- 

 hind only ; inner toe smallest and directed forwards, third 

 longest ; all the toes with two phalanges ; claws large, strong, 

 curved, tapering, very acute. Plumage soft, glossy ; no 

 bristles at the base of the bill ; wings extremely long, nar- 

 row and pointed ; the outer primaries a little incurved to- 

 ward the end, the first and second longest ; tail long, forked, 

 of ten feathers, much exceeded by the wings. 



Owing to the extreme shortness of their feet, the Swifts 

 are unable to walk efficiently ; but they cling with ease to a 

 perpendicular surface. Their flight is extremely rapid. 

 They nestle in holes in buildings, or in crevices of rocks, 

 forming their nests of materials gathered on wing. 



31. CYPSELUS MELBA. WHITE-BELLIED SWIFT. 



All the upper parts, together with the sides and lower part 

 of the neck, the sides of the body, legs, and lower wing and 

 tail coverts, greyish-brown ; the rest white ; length to end of 

 tail about nine inches. 



Male, 9, 21, 9 T V, A, T V, T 5 *> iV 



Only three specimens have been obtained in England, and 



