falconiDjE. 29 



is disposed in bars, which do not reach the margins of the feathers. The primaries are 

 white, their shafts, and one or two inches of their ends only, being blackish-brown ; they 

 are narrowly edged at the tips with white. The tail feathers and their coverts are entirely 

 white. The whole under surface of the bird is pure white, except the ends of the quill 

 feathers, which are hair-brown. The bill is pale greenish-gray, becoming darker at the tip. 

 Cere and lores wax-yellow. Legs yellow. 



Form, &c. — Bill short, strong, and much curved. The upper mandible has a rather 

 narrow ridge ; its cutting margin is undulated, having an acute tooth near its point, and an 

 obtuse lobe posterior to it. The under mandible is truncated at the tip, and deeply notched 

 on its cutting margin, for the reception of the upper tooth. The nostrils are round, with a 

 central pillar. The cere and lores are mostly covered with small white hairs and feathers, 

 arranged in a radiated manner. The icings are shorter than the tail ; the second quill 

 feather is the longest ; the third is a quarter of an inch, and the first half an inch shorter 

 than the second ; the fourth is half an inch shorter than the first, and more than an inch 

 shorter than the second ; the remainder diminish in succession an inch each. The first 

 and second have their inner webs sinuated, and the outer webs of the second and third are 

 also sinuated. The tail is nearly square. The tips of the thigh feathers reach to the roots 

 of the toes. The tarsus, rather more than two inches and a quarter long, is feathered for an 

 inch and three quarters ; its lower part being reticulated with crowded scales. The toes have 

 their first phalanges reticulated, and the others protected above by large transverse scales. 

 There is a short web between the outer and middle toes. The hind toe is shorter than the 

 others, and is armed with the longest nail ; the inner toe and nail are next in size : the 

 outer toe is rather longer and more slender than the inner one, and has the smallest nail of 

 all ; the middle toe is half an inch longer than these ; its nail being a little bigger than the 

 outer one. All the nails are strong, sharp, much curved, and grooved beneath. 



Inches. Lines. 



Length of the bill from the angle of the mouth 1 6 



of the tarsus . . .2 4 



of the middle toe . 2 



of the middle claw . .0 9 



The young Jerfalcons show little white on their plumage, being mostly of a dull 

 brown colour above. As they grow older, the white margins encroach 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 nar- 

 row transverse brown bars on the upper parts. Specimens are occasionally 

 procured totally white ; but whether they ought to be considered as birds in the 

 most perfect state of plumage, or merely as varieties, I have not been able to 

 ascertain. 





Dimensions, 



Inches. 



Lines. 



Length from the tip of the bill to the end of 



Len 



the tail . . . .24 







,, of the tail . . . . 10 



o 



,, of the longest quill feather . . 15 



,. 



„ of the bill, measured along its ridge . 1 



3 



