BIRDS AQUILINAE — P0LYB0RU8 THARUS. 



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appreciable specific differences between specimens from all parts of North America, and we may 

 be allowed to add, very slight between those of this country and of Europe and Asia. 



List of specimens. 



POLYBORUS, Vieillot. 



Polyborus, Vieillot, Analyse, p. 22, (1816.) 



Smaller than in either of the preceding genera of eagles. Bill rather long, compressed ; cere large ; wings long, pointed ; 

 tail moderate or rather long ; tarsi long, rather slender ; claws long, rather weak, and but slightly curved ; space in front of 

 and below the eye naked. 



Two species only form this genus, both of which, in their habits and manners, show an 

 approximation to the vultures. They are well known birds of South America. 



POLYBOKUS THAEUS, Molina. 



The Caracara Eagle ; The Mexican Eagle. 



Falco Iharus, Mol. Sagg. Stor. Nat. Chili, (1732.) 



Falco cheriway, JAcaniN, Beyt. Gesch. der Vog. p. 17, (1784.) 



Falco brasiliensis, Gm. Syst. Nat. I, 262, (1788.) 



Falco plancus, Miller, Cimelia Physica. 



Polyborus vulgaris, Vieill. Nouv. Diet. V, 257, (1816.) 



Figures.— Vieill. Gal. 1, pi, 7; Swains. Zool. 111. I, pi, 2 ; Gay's Chili, Orn.pl. 1 ; Aud. B. of Am. pi. 161 : Oct. ed. I, pi. 4. 



Legs rather long, occipital feathers somewhat elongated. Jldxilt. — Head and body above and wide belt on the abdomen and 

 tibite brownish black ; neck, breast, upper and under tail coverts yellowish white, on the breast with narrow transverse bauds 

 of black. Tail white at base, with numerous transverse bands of black and widely tipped with black ; bill bluish tipped with 

 yellowish white ; legs yellow. 



Younger. — Head and body above dull brown, darker on the head, and many feathers having paler edgings ; under parts dark 

 brown, with longitudinal stripes of dull yellowish white ; throat dull white ; tail for the greater part and its coverts above and 

 below white with numerous transverse bands of ashy brown, and lipped with brownish black. 



Total length, female, about 25 inches ; wing, 17 inches ; tail, 10 inches. 



Haft. — Southern North America. Florida. Texas. Mexico. Spec, in Nat. Mus. Washington, and Mus. Acad. Philadelphia. 



One of the most abundant of the rapacious birds of South America. It is of frequent 

 occurrence also in Mexico and Texas, and is found also in Florida. This bird is more sluggish 

 in its habits than is usual in this family, and may belong more properly to the family of 

 vultures. It subsists mainly on dead animals, and walks on the ground with facility. 



