Paraguay, Bolivia, and Southern Brazil. 105 



This species is nearly as abundant as M. honor iensts in 

 the Ajo district, and was the commonest Cow-bird observed 

 on the river expedition. 



The nests taken were found in the old nests of Anumbiiis 

 acuticaudatus, and contained eggs both of this species and 

 of ilf. rufoaxillaris, while, judging by the eggs found in the 

 nest of Pseudoleistes virescens, the eggs with large spots and 

 mottlings are those of M. rufoaxillaris, and those with the 

 more even markings belong to this species. 



58. DOLICHONYX ORYZIVORUS. 



Dolichonyx oryzivorus Scl. Cat. B. xi. p. 331. 



a. ? ad. Alto Paraguay, Bolivia. Oct. 15, 1909. 



Iris hazel ; bill, legs, and toes horu-brown. 



59. AgEL^US THILIUS. 



Ageleeus thilius Scl. Cat. B. xi. p. 343 ; Arg. Orn. i. 

 p. 97. 



a, b. ($ ad. Los Ynglases, Ajo. Sept. 1908. 

 Iris dark brown ; bill, legs, and toes black. 



c. ? ad. Los Ynglases, Ajo. Dec. 24, 1908. 



d. ? ad. „ „ Jan. 4, 1909. 



e. S imm. „ „ Feb. 16, 1909. 



f. g. (5* ad. et imm.; A. ? ad. Los Ynglases, Ajo. March 

 1909. 



i, k, I. c? ad. et imm. ; m. ? ad. Los Ynglases, Ajo. 

 April 1909. 



This is another common and resident species in the Ajo 

 district, and, as a rule, frequents the vast swamps or 

 caiiadons ; during the winter months it assembles in flocks 

 of several hundred individuals. 



The cup-shaped nest is composed of dry grass, and 

 is situated in the thick masses of grass in the swamps 

 only a foot or so above the level of the ground or water. 

 Three eggs appear to form the complete clutch. 



60. Agel^us ruficapillus. 



Agelaus ruficapillus Sc\. Cat. B. xi. p. 347; Arg. Orn. i. 

 p. 99 ; Claude Grant, Bull. B.O.C. xxv. p. 114 (1910). 

 a. c?. Mortero, Paraguay. Aug. 13, 1909. 



