MUSEUM OF COMPARATIVE ZOOLOGY. 359 



65. Larus sen-anus Tscn. " ' Gaviota.' Common. Nest about the 

 first of February, on little knobs of earth that project above the water. 

 Though their nests are frequently robbed, they continue to frequent the 

 6ame locality." Four specimens ; Moho. 



66. Rhynchops nigra Linn. " ' Aradora.' Rare ; perhaps accidental. 

 The single specimen taken was seen by many people, but none had seen it 

 on the lake before, and regarded it as a stranger. The sailors, who had 

 seen it before along the sea-coast, were sure it did not belong here." 



67. Centropelma micropterum (Gould). <" Sondeador.' ' Samboul- 

 lidor.' Very common about all parts of the lake, where the water is at all 

 shallow. Feeds on fishes, batrachians, etc. In February younf were taken 

 about two-thirds grown. They are unable to rise from the water, but by 

 flapping their rudimentary wings and striking the water with their feet they 

 manage to progress quite rapidly for a considerable distance. They dive 

 quickly at the discharge of a gun, — so quickly that unless taken unawares 

 will dodge the shot, — and escape, often swimming a long distance under 

 water before reappearing." Thirteen specimens were obtained of this rare 

 species, which seems mainly confined to this lake. 



68. Podiceps caliparseus Less. Two specimens ; Moho. 



69. Podiceps Rollandi Quoy & Gaim. " ' Sondeador.' Common. 

 Found in company with Centropelma micropterum. Like that species it 

 never attempted to fly, but is very quick in diving, and hence is difficult to 

 shoot." Five specimens ; Carapata. 



Cambridge, April, 1875, 



