NATURAL SCIENCES OP PHILADELPHIA. 91 



Neot. 1873, 119. Sharpe, Cat. Ace. B. M. 1874, 172. Taehytriorehis 

 erythronotus, Bonap., consp. 17. Pceciloptemis erythronotus, Kaup, 

 Contr. Orn. 1850, 76. Bonap. Consp. I., 1850, ll.Aquila braccata, 

 Meyen, Beitr, 1834, Q5. Buteo bracchatus, Pelz. Verb., z.-b. "Wien, 

 1862, 12. Buteo tricolor, D'Orb. et Lafr. Syn. Av. 1838, 6. D'Orb. 

 Voy. Am. Merid. 1840, 69, 106, pi. 30. Buteo unicolor, D'Orb. et 

 Lafr. 1. c. p. 7 ' .Bypomorphnus leucurus, Lafr. R. Z. 1849, 338. 

 Buteo polyosoma, Schl. Mus. P.-B. Buteones 1862, 12; Rev. Ace. 

 1873, 109 (not of Quoy and Gaim !). 



Habitat. Pacific slope of South America, from Peru to Falk- 

 land Islands; Chile; Patagonia, on both coasts, up to 40. 



Diagnosis. Dimensions. Wing, 14.25-16.30; tail, 7.30-9.00; 

 culmen, .83-1.00 ; tarsus, 2.95-3.50 ; middle toe, 1.30-1.50. Form: 

 Third or fourth quill longest ; first intermediate between eighth 

 and ninth. Tail even in the adult, slightly rounded in the young. 

 Color: Adult, tail pure white (the lateral feathers scarcely 

 tinged with ash), crossed near the end by a subterminal band of 

 uniform black about 1.00 wide ; the white portion crossed by 

 fine lines or narrow bars of plumbeous. Above, including the 

 rump, and sides of the neck, mostly or wholly uniform plumbe- 

 ous ; throat, cheeks, and rest of lower parts pure white, the sides 

 (always), frequently the abdomen and usually the tibiae more or 

 less barred with plumbeous. %. Upper parts entirely uniform 

 plumbeous, without any rufous. ?. Back and scapulars uniform 

 bright rufous. Young. Tail hoary ash, uniform, or growing 

 gradually paler basally, with a narrow dusky subterminal band, 

 and narrowly barred to the base with dusky, these bars sometimes 

 nearly obsolete or broken into an irregular mottling. Above 

 blackish-brown, much variegated, especially on the wing-coverts, 

 scapulars and upper tail-coverts, with ochraceous or rufous. 

 Lower parts ochraceous or ochraceous-white, the middle of the 

 breast usually inmaculate, but the sides of the breast, the sides 

 and the abdomen marked with broad transverse bars of rusty or 

 longitudinally cuneate spots of brownish-black ; the breast some- 

 times with narrow streaks of the same ; tibiae and crissum with 

 narrower rusty bars, or hastate spots. 



Remarks. In the adult there is sometimes an entire absence 

 of bars on the white portion of the tail. One adult female has a 

 few rufous feathers on the sides of the breast. 



A young male is marked as follows : 



Tail hoary ash, narrowly barred to the base with darker, and 



