GYR-FALCON. 41 



lour above. As they grow older, the white margins en- 

 croach on the brown, which becomes merely a central 

 blotch, indented on each side by the white ; while in aged 

 birds the plumage is mostly pure white, varied only by a 

 few narrow transverse bars on the upper parts." 



These coinciding observations from two distinguished 

 naturalists render any attempt at a technical description 

 unnecessary, beyond adding that the specimen from which 

 the present figure was taken measured twenty-three inches 

 in length from the point of the beak to the end of the tail : 

 the beak itself pale bluish horn colour, the cere yellow ; 

 the irides dark, as are those of all the true Falcons : the 

 head, neck, chest, under surface of the body, and under 

 tail-coverts, become pure white before the greyish brown 

 spots and bars are lost on the back and upper surface of 

 the wings; the wing-primaries are dark at the tip, but 

 do not reach to the end of the tail : the tarsi and toes 

 are yellow; the claws black, curved, and sharp. 



