48 
FALCONING. NAUCLERUS. FALCO. 
resembling that of the Owls ; stomach very large, round, its 
muscular coat very thin ; intestine short and rather wide ; 
no coeca ; cloaca large, globular. Nostrils round, with a 
central papilla. Eyes large. Aperture of ear roundish and 
rather large. Head roundish, flattened above ; neck short ; 
body compact. Feet short, tarsus very short, robust, covered 
all round with scales : toes of moderate size, scutellate above ; 
claws rather long, well curved, slender, acuminate. Plumage 
blended, glossy ; wings extremely elongated, rather narrow, 
pointed, the third quill longest ; tail extremely long, very 
deeply forked. 
9. Nauclerus furcatus. White-headed Swallow-Kite. 
Head, neck, and lower parts white ; back, wings, and tail 
black ; bill bluish-black, feet greenish, claws flesh-coloured. 
Male, 22, 4/, 18, 
This bird is distinguished from all the British falconine 
species by its very long and deeply forked tail, as well as by 
its peculiar colouring. Its proper country is the tropical and 
temperate regions of America. Two individuals, however, are 
recorded as having been met with in Britain : one killed at 
Ballychulish in Argyleshire, in 1772 ; the other caught at 
Shawgill in Yorkshire, in September 1805. Its flight is 
described as singularly beautiful, its motions astonishingly 
rapid. It generally feeds while on wing ; and its food con- 
sists of grasshoppers, insects, small snakes, lizards, and frogs. 
Swallow-tailed Hawk. Swallow-tailed Kite. 
Falco furcatus, Linn. Syst. Nat. i. 129.-— Falco furcatus, 
Audubon, Orn. Biog. i. 368 ; v. 371. — Nauclerus furcatus, 
Aud. Synop. 14. — Nauclerus furcatus. White-headed Swal- 
low-Kite, MacGillivray, Brit. Birds, hi. 277. 
GENUS IX. FALCO. FALCON. 
Bin short, very strong, of nearly equal breadth and height 
at the base, moderately compressed toward the end ; upper 
mandible with the dorsal line convex from the base, the sides 
convex, the edges with a medial festoon and an anterior 
angular process, the tip decurved, trigonal, acute ; lower 
mandible with the angle wide and rounded, the dorsal line 
very convex, the edges involute, with a rounded notch on 
