90 NORTHERN ZOOLOGY. 



margin of the cere. Facial circle of wiry feathers small and very incomplete, being visible only 

 at the base of the bill and beneath the orbit. The eyebrow projects as in the Falcons, and is 

 clothed with plumage similar to that on the crown of the head. The bristly feathers at the 

 base of the bill project forwards and cover the nostrils. Tips of the folded wings about an 

 inch and a half shorter than the tail. The third quill feather is the longest ; the fourth is 

 three lines, and the second four or five lines, shorter than the third* ; the fifth is an inch and 

 a quarter shorter than the fourth ; the first is an inch and a half shorter than the second, or 

 about a quarter of an inch shorter than the fifth ; the others diminish successively about an inch 

 each ; the second, third, and fourth have their outer webs abruptly narrowed, or notched ; and 

 the first to the fourth inclusive have also very deep and abrupt notches on their inner webs. 

 The barbs of the outer web of the first feather have their points reverted and open y : this is 

 also the case, though in a less remarkable degree, on the outer margins of the narrowed part 

 of the three succeeding feathers. The under tail coverts are nearly as long as the tail, and 

 have pretty strong shafts, with very downy webs at their bases. The tail is rather short 

 and rounded, its exterior feathers being nearly an inch shorter than the middle ones. The 

 claws, when the leg is stretched out, reach within three inches and a half of the end of the 

 tail. The thigh feathers reach to the feet. The tarsi are short. The feet and toes are 

 covered with long white hairlike feathers, which partly conceal the claws : by turning these 

 hairs aside, two scales may be seen at the base of each claw above. The feathers on the back 

 part of the tarsus are particularly long and somewhat downy. The inner claw and the middle 

 one are equal in size, both are grooved beneath, and the latter has a very sharp interior edge. 

 The two others are rounded beneath and are smaller, particularly the hind one, which is the 

 shortest of all. All the claws are much curved and very sharp. 



Dimensions. 



Inches. Lines. Inches. Lines. 



Length from the tip of the bill to the end of Length of the bill in a straight line from the 



the tail ...... 25 6 corner of the mouth 



,, of the tail .... 9 6 ,, of the tarsus .... 



„ of the longest quill feather 16 ,, of the middle toe 



„ of the bill, measured along its ridge 1 9 ,, of its claw, following its curvature 



,, of the cere on its ridge . . 9 „ of the fore claw in a straight line 



Temminck remarks, that the younger the individuals are, the more is their 

 plumage spotted and barred ; and that the very old birds are pure white, without 



* There is some variation in the lengths of the quill feathers in different specimens. The second, third, and fourth 

 are obviously longer than the others in all, the second and fourth being nearly equal. The first quill feather is some- 

 times longer than the fifth. 



-j- The different formation of the exterior laminae of the quill feathers, in Falcons and Owls, does not appear to have 

 excited that attention which the subject deserves. In Falco sparverius, and probably in all the kindred species, the 

 external laminae of the quills are concave, with a semi-central shaft, analogous to the quill itself. The outer vane is 

 formed of still more minute lamina? ; but the inner vane, which is by far the broadest, is perfectly entire, and of a 

 horny texture, being concave beneath : it thus reposes, with great compactness, upon the next lamina of the quill. In 

 the Owl this structure is beautifully modified to admit a free passage for the air, by which the flight of these birds is 

 noiseless. The horny vane above mentioned is no longer entire, but is split into minute laminae along its entire length ; 

 the end, instead of reposing on the next, is recurved outwards, thus giving the appearance of a dentated margin.— Sw. 



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