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220 



CATHAETIDiE, AMEEICAN VULTURES. GEN. 165. 



Obs. The Greenland Sea Eagle, //. albiciUa; and the Northern Sea Eagle, H. 

 pdagkus (Cass., 111. 31, pi. 6, and in Bd., 42, 43 ; Elliot, pi. 34, 35), both usually 

 attributed to our fauna, remain to be detected, the former in N. E., the latter 

 in N. W., portions. H. pelagicus has 14 rectrices, and is otherwise distinct. 



FIG.IW. Bald Eagle. 



c^y 



165. Genus POLYBORUS Vieillot. 



Caracara Buzzard. Biil long, high, compressed, little hooked, commis- 

 sure nearly straight to the deflected end ; nostrils linear, oblique, in the front 

 upper corner of the cere, which is truncate and bristly ; sides of head 

 extensively denuded ; occipital feathers lengthened ; 3d and 4th cjuill longest, 

 1st shorter than 7th; outer 4-5 emarginate ; tarsus almost naked, longer 

 than middle toe. Brownish-black, barred on the iieck, breast and most of 

 the upper parts, with yellowish-white; auriculars whitish; tail whitish, 

 narrowly black-barred and with broad black terminal zone ; primaries like- 

 wise barred with whitish; feet yellow; bill greenish-white. Length 23; 

 wing 15-17; tail about 10. Southern border, Florida to California; a 

 remarkable form, allied in some respects to the vultures. Aud., i, 21, pi. 

 4; NuTT., i, 52; Cass, in Bd., 45; Coop., 492. tiiarus var. audubonii. 



Family CATHARTIDiE. American Vultures. 



Head, and part of the neck, more or less completely bare of feathers ; ej^es flush 

 with the side of the head, not overshadowed by a superciliary shield ; ears small 

 and simple. Bill lengthened, contracted toward the base, moderatelj' hooked aud 

 comparatively weak. Nostrils very large, completely perforated, through lack of a 

 bony septum. Wings very long, ample and strong ; tail moderate. Anterior toes 

 long for the order, webbed at base ; hind toe elevated, verjr short ; claws compara- 

 tively lengthened, obtuse, little curved and weak. To these external characters, 

 which distinguish our vultures, I may add, that there are numerous osteological 

 peculiarities. A lower larynx is not developed. The capacious gullet dilates into 

 an immense crop. The coeca are extremely small. The feathers lack an aftershaft. 



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