776 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



SiPTORNIS SORDIDA FLAVIGULARIS Gould. 



Synallaxis flavigularis Gould, Voy. Beagle, Birds, p. 78, pi. 24 (1841) 

 (Bahia Blanca: Santa Cruz). 



Description. — Adult male, 284502 Biol. Survey Colin., U. S. Dept. of 

 Agriculture, General Roca, Rio Negro, Argentina, November 27, 1920, 

 Alexander Wetmore. Total length, 5.80 inches; wing, 2.25; culmen, 

 .41; tail, 2.98; tarsus, .70. Above dull wood brown (Ridgway), wings 

 somewhat rufescent, tail darker brown, two outer pairs of feathers largely 

 rufous as well as the outer web of the next pair; below pale ashy flanks 

 and under tail coverts browner; a patch of dull orange on the upper 

 throat, each feather minutely tipped with black, lores dull white, bill and 

 feet black, under mandible pale at base. 



Female similar, but throat spot paler and tips largely white; imma- 

 ture birds lack the orange spot, the upper throat being white. 



GeograpJiical Range. — Patagonia and southern Argentina (Buenos 

 Aires, Mendoza, Rio Negro). 



In the Huanuluan-Maquisuchao region Mr. Peters found it to be the 

 common Spring-tail frequenting the thicker and denser growths of bushes 

 from the end of October to the end of December. 



SiPTORNIS BAERI Bcrlcpsch. 



Siptornis baeri Berlepsch, Bull. Brit. Orn. Club, xvi. p. 99, 1906 (Cos- 

 quin, Cordova). 



Description. — Adult male, 284498 Biol. Survey Colin., U. S. Dept. of 

 Agriculture, Pampa Victoria, Argentina, December 28, 1920, Alexander 

 Wetmore. Similar to S. sordida flavigularis but tail much shorter, bill 

 shorter and decidedly heavier, lower edge of throat-patch often blackish 

 and feathers only slightly tipped with black, if at all ; wings grayer, less 

 tawny, but crown tinged with tawny. 



Adult female has throat spot smaller and lacks the black, feathers 

 tipped with white ; immature female shows it only faintly and immature 

 male has a blackish spot with only a suggestion of orange. Immature 

 birds also have obscure transverse dusky streaks to the feathers of the 

 breast. 



Total length, 5.50 inches ; wing, 2.37 ; culmen, .39 ; tail, 2.40 ; tarsus, .83. 



Geographical Range. — Western Argentina as far south as the Rio Col- 

 orado (Peters) and Rio Negro (Doering). 



