348 Mr. C. II. B. Grant on Birds collected in Ai'gentina, 



The only difference between the pair ol: young shot in 

 December lies in the male haviog a considerably darker 

 speculum ; both are moulting on the back. The young 

 female taken in April is moulting all over, except for the 

 wings, and bas already assumed the rufescent head, breast, 

 and back feathers of the adult ; the speculum is pale 

 brown, blackish where it adjoins the light tips and on the 

 inner webs. 



This is perhaps the commonest i Duck on the pampas of 

 the Ajo district; at the time that the thistle-seed is ripe 

 (January to April) enormous flocks visit the open camps, 

 resting by day on the lagunas, wliere excellent shooting can 

 be obtained at the regular morning and evening flights. 



It breeds in the district, placing the nest under any 

 convenient tuft of grass, thistle, &c., in the open camp ; the 

 structure is lined with down and six to nine eggs are laid. 

 The bird sits closely, and usually only rises when one's horse 

 almost steps on the nest. 



Thirteen eggs were brought home, collected on Oct, 22nd, 

 1909, at Ajo. They measure : axis 2-0 to 3-3 in., diam. 1-41 

 to 1-55. 



222. Dapila bahamensis. 



Dajila bahamensis Arg. Orn. ii. p. 135. 

 Pcecilonetta bahamensis Salvad. Cat. B. xxvii, p. 282. 

 a. ^ ad. Luiconia, Ajo. Feb. 23, 1909. 

 Irides crimson ; bill black, slaty at tip, basal patch red ; 

 legs and toes ash-coloured. 



223. Mareca sibilatrix. 



Mareca sibilatrix Arg. Orn. ii. p. 135 ; Salvad. Cat. B. 

 xxvii. p. 23G. 



a,b.S^ ad. Los Ynglases, Ajo. Sept. 15-23, 1908. 



c. S ad. „ „ Jan. 19, 1910. 



Irides dark brown ; bill, upper mandible blue slate- 

 coloured, tip next to feathers and lower mandible black ; 

 legs and toes blue-grey. 



The January bird is shewing considerable signs of wear 

 and is beainning to moult. 



