Paraguay J Bolivia, and Southern Brazil. 473 



resident, breeding, I was told, near Cape San Antonio. In 

 its habits it resembles L. marinus. 



270. Larus maculipennis. 



Larus maculipennis Arg-. Orn. ii. p. 198 ; Saunders, Cat. 

 B. p. 200. 



a. ? ad. Los Ynglases, Ajo. Sept. 11, 1908. 



b. S iii'm- „ „ Sept. 11, 1908. 



c. S imm. „ „ Oct. 14, 1908. 



d. c? ad. „ „ Jan. 14, 1909. 



e. cJ ad. „ „ Jan. 27, 1909. 

 /. ? ad. Luiconia, „ Feb. 2, 1909. 



ff. (^ young. Los Ynglases, Ajo. Feb. 9, 1909. 



h. ? imm. „ „ Apr. 3, 1909. 



i,j. S ? ad. „ „ Apr. 14-20, 1909. 



k. S ad. „ „ June 11, 1909. 



/, m. S ad. „ „ Dec. 22-23, 1909. 



n. S ad. „ „ Jan. 18, 1910. 



This is the commonest Gull iu the Ajo district, and is 

 resident ; but, owing to the dry seasons, it did not breed 

 in the camp, and I believe repaired to Cape San Antonio 

 for that purpose. It was also observed some way up the 

 Parana, and I have recorded that several were seen near 

 La Paz, N. Argentine, with completely brown heads, on 

 July 17. 



271. Larus cirrhocephalus. 



Larus cirrhocephalus Arg. Orn. ii. p. 201 ; Saunders, Cat. 

 B. XXV. p. 198. 



a. (S ad. Los Ynglases, Ajo. Mar. 29, 1909. 



b. ? imm. „ „ Mar. 29, 1909. 



c. ? ad. „ „ Mar. 30, 1909. 



d. S ad. „ „ Mar. 31, 1909. 

 ej, ? ad. „ „ Mar. 31, 1909. 

 g. $ imm. „ „ Apr. 1, 1909. 

 h. J ad. „ „ Apr. 10, 1909. 



The Grey-headed Gull makes its a]3pearance in the Ajo 

 district after the breeding-season and remains throu<;hout the 



