72 
CYPSELINtE. cypselus. 
GENUS XYIII. CYPSELUS. SWIFT. 
BiU 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, 
a*rched. Upper mandible shallow, with a slightly promi- 
nent central line ; palate flat ; tongue short, sagittate and 
papillate at the base, bifid at the tip ; oesophagus 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. 
Nostrils 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, 
Only three specimens have been obtained in England, and 
