254 



NORTU AMERICAN BIRDS. 



Onychotes gruberi, Ridgavay. 



OBVBEB'S HAWK. 



Onyclwtes gruberi, Ridoway, Pr. Ai-. Nat. Sc. Phil. Dec. 1870, p. 149. 



Sp. CnAK. Immature? (41,703, "California"; F. Gruber). OuUstrctclied foot reachinij 



beyond tail. General phiniage dull dark-bistre, 

 with a f^ray isli-uniberca.st in some lights, darke.st 

 on the head above an<l back ; the po.sterior 

 lower parts paler and more reddish ; throat 

 and neck much tinged with pale rusty (this 

 obsoletely bordering the feathei's, which here 

 have fine whitish filaments attached to the 

 shafts) ; primaries uniform black. Tail like 

 the rump, but with a more hoary tinge (not 

 paler at the tip), and crossed with seven or 

 eight very narrow obscure bars of darker, the 

 last of which is distant an incli or more from 

 the end. Lining of wing dark bistre, much 

 tinged with rusty, this prevalent toward the 

 edge; under surface of primaries white an- 

 terior to their emargination, beyond which 

 they are ashy, approaching black at ends ; 

 ashy portion with distant, very obsolete, dusky 

 bars, Ijut the cheeks and throat streaked obso- 

 letely with this color. Xo distinct white any- 

 where about the head or neck. Wing, 10.00; 

 tail, 5.80; tarsus, 2.70; middle toe, 1.40; inner, 

 .90; outer, 1.10; posterior, .80; hind claw, 

 1.00 (chord) ; inner claw, .91 ; on front of 

 tarsus, twelve exposed largo transverse scu- 

 telUe ; only 1.70 of the tarsus exposed. 



Onychotes gruberi. 



The typo of tliis species still remains 

 unique. It was sent to the Smithsonian Institution by Mr. Gruber, who 

 labelled it as having been obtained in California. Nothing is known of its 

 habits. 



^Si-. 



Genus BXTFEO, Cuvier. 



Buteo, Ctrv. 1799. (Tj-po, Fulco biileo, Linn. = Buleo vulgaris, Bechstein.) 

 Cr-axircr, GorLD, 1838. (Type, Buko galapayocnsix, Goitld.) 

 PoKihpternis, K.vri', 1847. (Type, Faico borcalis, Gm.) 

 Tachijtriorchis, Kaup, 1844. (Type, Falco pterodes, Tkm.m.) 



Gen. Char. Form robust and heavy, the wings long, and rather pointed, the ' ill 

 moderate and rounded, the bill and feet strong. Bill intermediate between that oi Ant fir 

 and that of Parabuteo. Wing long and rather pointed, the third to fifth quill longest, tlie 

 first shorter than eighth ; three to lour with inner webs emarginated. Tail moderate, 

 slightly rounded. 



