260 Proceedings of the Biological Society of Washington. 



Xenops rutilus rutilus. Brazil: Chapada, 15; near Corumba, 2; Sao 

 Paulo, 1. 



Xenops rutilus heterurus. Colombia: 24. Trinidad: 1. Ecuador: Zar- 

 uma, 6; Naranjo, 1. Peru: Idma, 2; San Miguel Bridge (Urubamba 

 Canon), 3; San Miguel River, 1. 



Xenops tenuirostris. Brazil: Barao Melgaco, Matto Grosso, 2; Rio 

 Roosevelt, 1 (heretofore known only from the type). 



Remarks. — This is a most interesting link between Xenops rutilus rutilus 

 of Brazil, and X. r. heterurus of the Andes from southern Peru northward 

 and northern South America. Like true rutilus it has only one pair of tail- 

 feathers with the inner web wholly (or almost wholly) black. It differs 

 from true rutilus, however, in being more olivaceous and more narrowly 

 streaked below, in having the back darker, the crown black and more finely 

 streaked. In general color characters it therefore resembles heterurus, but 

 has only one pair instead of two pairs of rectrices, largely black. 



Xiphorhynchus triangularis bangsi, hew subspecies. 



Subspecific characters. — Similar to Xiphorhynchus triangularis triangu- 

 laris (Lafr.), but general coloration, particularly of the upper parts, slightly 

 less olivaceous, more rufescent; the bill largely whitish or horn-color, 

 usually black only at the base and end of the maxilla; the buffy markings 

 on the crown larger, the back with buffy shaft-streaks; the rump more 

 rufous; the throat and markings of the under parts white; the markings 

 of the breast smaller and not extending to the abdomen, which is narrowly 

 streaked instead of spotted; under tail-coverts with fine, instead of broad 

 shaft-streaks. 



Type.— No. 137,388, Am. Mus. Nat Hist., ? ad., Yungas, alt. 3600 ft., 

 Prov. Cochabamba, Bolivia, June 10, 1915; Miller & Boyle. 



Range. — Subtropical zone of the eastern slope of the Andes in Bolivia 

 and in Peru, at least north to Garita del Sol. 



Specimens examined. — Xiphorhynchus triangularis bangsi. Bolivia: 

 Yungas, type locality, 1 ; Locotal, 5800 ft., 1. Peru: San Miguel Bridge, 

 Urubamba Canon, 2; San Miguel River, 4500 ft., Urubamba Canon, 1; 

 San Miguel Road, 6000 ft., 1; Idma, above Sta. Ana, 5000 ft., 1. 



Xiphorhynchus triangularis triangularis. Colombia: 34 specimens in- 

 cluding the type and topotypical series. Ecuador: Zamora, Prov. Loja, 4. 



Remarks. — Mr. Hellmayr's belief 1 that the type of Lafresnaye's " Den- 

 drocolaptes triangularis" came from Bogota, not Bolivia, as stated in the 

 original description, is confirmed by an examination of Lafresnaye's type, 

 now in the collection of the Museum of Comparative Zoology (No. 77,147; 

 Lafr. Coll., No. 2275), whence it has been loaned me by Mr. Bangs. On 

 the original label the words "Colombie, Bogota," are written over the 

 word "Bolivia." Lafresnaye having discovered the error in the alleged 

 type-locality apparently corrected it on the label of the type as he did also 

 in his monograph of the group to which the bird in question belongs (Rev. 

 Mag. Zool., 1850, p. 419). The type is faded and the bill is broken, but 



lHellmayr, P. Z. S , 1911, p. 1153, foot-note. 



