222 ROUGH-LEGGED FALCON. 



Male. Female. 



Length to end of tail, . . 21| 23 



wings, . 21^ 23 



claws, . 19 21 



Extent of wings, . . . 51^ 55i 



These measurements, with those previously given by myself and 

 Wilson, and those to follow, shew that, like many other birds, the 

 Rough-legged Buzzards differ considerably in size. 



In order to render the history of this bird as complete as possible, 

 I shall here describe an adult male, an adult female, a young male in 

 its first plumage, a young male in its second plumage, and an indivi- 

 dual in the intermediate state. 



Adult Male. Plate CCCCXXII. Fig. 1. 



Bill short, as broad as deep at the base, compressed toward the 

 end ; upper mandible with the cere rather short, the dorsal line nearly 

 straight and declinate as far as the edge of the cere, then decurved, 

 the ridge convex, the sides slightly convex, the sharp margin perpen- 

 diculai-, with a slight festoon, succeeded by a broad sinus, the tip tri- 

 gonal, descending obliquely ; lower mandible with the angle wide, the 

 dorsal line convex, the back broadly convex, the sides convex, the 

 edges sharp, arched, and inflected, the tip obliquely truncate. Nos- 

 trils large, subovate in the fore part of the cere. 



Head large, broad, flattened above, with the superciliary ridges pro- 

 minent. Eyes large. Neck of moderate length, body robust. Feet 

 rather short, robust ; tarsi roundish, feathered in their whole length ; 

 toes short, and rather small ; hind toe considerably shorter than the 

 second, the fourth smallest and connected with the third by a small 

 membrane ; all with four scutella at the end, the rest of their upper 

 parts covered with very small hexagonal scales. Claws long, mode- 

 rately curved, rather slender, considerably compressed, flat beneath, 

 tapering to a fine point. 



Plumage remarkably soft, full, and rather blended. Space between 

 the bill and eye covered with dark bristle-tipped downy feathers. 

 Feathers of the head and neck lanceolate, of the back and breast broad 

 and rounded, of the legs short and narrow, excepting the outer tibial, 

 which are elongated and oblong. Wings long, reaching to the end of 

 the tail ; the first four quills abruptly cut out on the inner web ; se- 



