ORDER ACCIPITRES. 31 



The genus Harpagus of Vigors, and the Bidens of 

 Spix, have the bill and tarsi of Hierax ; but the 

 third and fourth quills are the longest, as in the 

 Sparrow Hawks. 



Notched Falcon, hsLth. {F. bidentatus, hath. pi. col. 

 38. jun. 228.) 



Above gray, brighter on the head and cheeks ; be- 

 neath reddish, rayed with white ; throat and lower 

 tail-coverts white ; bill ash gray ; feet and cera yel- 

 low. Length fourteen inches. South America, when 

 young. PI. col. 228, and Spix, t, 7 : it is the Bidens 

 albiventer of Spix ; and B. rujiv enter of Spix, t. 6, 

 is, perhaps, a variety. 



Two-toothed Falcon. (F. diodon. Temin. pi. col. 

 t. 198.) 



Above blackish; back of head, cheeks, and side of 

 the neck deep grey ; below pale grey ; throat white ; 

 thighs reddish ; wings and tail rayed with black : 

 length eleven inches. Brazil. \t \s, Bidens cinerascenSi 

 and B. femoralis of Spix, t. 8. 



TAe Gerfalcons, (Hierofalco, Cwv.) 



Have the quills of the wings as in other noble birds, 

 to which they are assimilated, except that the beak 

 has only a festoon, as in the ignoble birds. The 

 tail, long and displayed, exceeds the wings, although 

 the latter are very long. Their tarsi, short and 

 reticulated, are feathered to the upper third. Only 

 one species is well known. 



