486 PATAGONIAN EXPEDITIONS : ZOOLOGY. 



more outer primaries seal-brown like the back ; secondaries white, over- 

 cast with a shading of seal-brown, and with narrow tips of darker seal- 

 brown like the back, the whitish area forming a speculum, defined pos- 

 teriorly by the dark tips ; the tertials are glossy obscure green ; the upper 

 wing-coverts are deep seal-brown concolor with the back, there is a well 

 defined whitish margin to the shoulder and the greater series of the 

 upper wing-coverts are glossy obscure greenish, forming a boundary an- 

 teriorly to the speculum ; the under wing-coverts are whitish, except some 

 darker marginal ones ; the axillaries are white, the longer ones being 

 vermiculated on their tips with pale seal-brown. 



Lower parts : Chest deep seal-brown, washed with cinnamon-chestnut ; 

 the breast and anterior lower surface deep seal-brown, each feather so 

 broadly tipped with silvery white as to obscure the ground color, which 

 barely shows through ; the sides and flanks snuff-brown, with a strong 

 chestnut shading ; the belly and vent seal-brown, pale in shade, each 

 feather with the border powdered or vermiculated with silvery whitish ; the 

 lower tail-coverts immaculate white, almost hiding the rectrices. 



Bill : With little or no basal wattle. In color blackish, shaded with 

 orange ; nail dark horn-color. 



Feet : The feet and legs are brown, shaded with greenish and obscure 

 orange. 



Iris : Deep hazel-brown. 



The young of the year and downy young are not represented in the 

 collections. 



Geographical Range. — Central South America from southern Brazil, 

 Paraguay, Uruguay and northern Chili southward, through Argentina, to 

 Patagonia (Burmeister) ; rare in southern South America. 



This duck was not observed or taken by Mr. Hatcher or his assistants 

 in Patagonia and it is doubtful if the bird occurs at all commonly south 

 of the Rio Negro in Argentina. It is common throughout northern 

 Argentina, particularly in the Province of Buenos Aires, where it is resi- 

 dent and breeds in numbers in the interior. In the British Museum there 

 are sets of eggs from this region collected in October (20), and others in 

 November ; a set from central Chili was collected in October. Mr. Bar- 

 rows in his travels through northern Argentina and Uruguay says of this 

 duck : "Very abundant on the Uruguay in times of freshet and probably 



