﻿BIRDS OF PREY. EAGLES. 



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as a distinct type. The above four subgenera are all 

 that we can admit into the accipi trine circle ; and it 

 consequently follows that there still remains another to 

 be determined by future observation or discovery : this, 

 according to our theory, will be the tenuirostral type, 

 which in the present instance must alike represent 

 Aviceda and Cymindis ; in other words, it must be a kite 

 among the hawks. Several of the birds arranged among 

 the smaller eagles and the larger buzzards will probably 

 be found, upon actual examination, more naturally allied 

 to the N aberrant hawks, especially such as Buteo borealis, 

 pterocles, &c. 



(248.) The genus Aquila is the first of those com- 

 posing the aberrant division of the family wherein the 

 upper mandible of the bill shows little or no indication 

 either of the acute tooth of the falcons, or the promi- 

 nent but rounded lobe of the hawks. We have a 

 perfect example of this shaped bill in the white-headed 

 hawk, forming the type of the restricted subgenus 

 Halicetus, and the bill of the osprey is nearly the same ; 

 but as we approach the more typical eagles, the length 

 of the bill is greater, the size of the body is aug- 

 mented, and all indications of the accipitrine structure 

 are lost. These circumstances deserve attention, because 

 they afford a strong ground for considering the true 

 fishing eagles (Pandicn) as a prominent, although an 

 aberrant, type in the aquiline circle ; a station which 

 still further confirms that which we have given to Ha- 

 licetus. The typical eagles appear to arrange them- 

 selves, as M. Cuvier has intimated, under two leading 

 groups or subgenera, chiefly distinguished by the struc- 

 ture of their wings. To those whose wings, like the 

 golden eagle, are more or less lengthened, we restrict 

 the subgenus Aquila, more for the sake of not creating 

 a change of nomenclature among the best known species, 

 than from any belief that they are the pre-eminent 

 types of the aquiline group. The legs of these birds 

 are all more or less plumed ; and in one species, the 

 wedge-tailed eagle of New Holland (A. fucosa, Cuv., 

 x 2 



