298 The Naturalist in La Plata. 



same time an internal note with great vehemence ; 

 and suddenly, as the danger comes nearer, they 

 plunge simultaneously, with a startled cry, into 

 their burrows. But in some curiosity is the 

 strongest emotion; for, in spite of their fellow's 

 contagious example, and already half down the en- 

 trance, again they start up to scrutinize the stranger, 

 and will then often permit him to walk within five 

 or six paces of them. 



Standing on the mound there is frequently a 

 pair of burrowing owls (Pholeoptynx cunicularia). 

 These birds generally make their own burrows to 

 breed in, or sometimes take possession of one of the 

 lesser outside burrows of the village ; but their 

 favourite residence, when not engaged in tending 

 their eggs or young, is on the vizcachera. Here a 

 pair will sit all day ; and I have often remarked a 

 couple close together on the edge of the burrow ; 

 and when the vizcacha came out in the evening, 

 though but a hand's breadth from them, they did 

 not stir, nor did he notice them, so accustomed are 

 these creatures to each other. Usually a couple of 

 the little burrowing G-eositta are also present. They 

 are lively creatures, running with great rapidity 

 about the mound and bare space that surrounds it, 

 suddenly stopping and jerking their tails in a slow 

 deliberate manner, and occasionally uttering their 

 cry, a trill, or series of quick short clear notes, re- 

 sembling somewhat the shrill excessive laughter of 

 a child. Among the grave, stationary vizcachas, of 

 which they take no heed, perhaps half a dozen or 

 more little swallows (Atticora cyanoleuca) are seen, 

 now clinging altogether to the bank-like entrance 



