252 J^otes 071 JVatural History. [May, 



crawling along over the surface of the ground, their curiosity 

 seems to be excited to such a degree that they without hesitation 

 gradually draw near the object of their wonder as if for its grat- 

 ification, and it is in this manner that the Indians decoy them into 

 shooting distance and destroy them in great numbers. It is in 

 the pursuit of these animals and the guanaco, that the puma or 

 South American lion is frequently enticed down into the plains, 

 and their destruction is speedily accomplished by. either disloca- 

 ting or fracturing their necks, as the skeletons of those which 

 have become victims to these beasts of prey, upon inspection, have 

 universally presented this appearance. 



Inhabiting the vicinity of rivers and fresh water lakes, is to be 

 found the largest rodent, or gnawing animal, hitherto known to 

 naturalists, the Hydrochaerus capybara or water-hog. I know 

 not of its being found in this immediate neighborhood, but am 

 informed that it is exceedingly common a few degrees to the 

 north, particularly along the tributaries of the river Plata. 

 They grow to some considerable size, frequently attaining a 

 weight of nearly a hundred pounds, and when seen at a dis- 

 tance, greatly resemble pigs, but on closer inspection their rela- 

 tion to the cavies and rabbits is strikingly perceptible. They 

 appear very tame, particularly in situations where they are not 

 often molested by the jaguar and other beasts of prey. A fossil 

 species closely connected with this, has recently been found in 

 the redish clay of these plains, associated with immerous other 

 extinct and gigantic quadrupeds. 



There is another singular little animal inhabiting this place in 

 great numbers which is rarely seen above the ground. Its habits 

 are nocturnal, and very similar to those of the mole, burrowing in 

 ramifying trenches just beneath the surface of the soil, for un- 

 known distances, and throwing up small hillocks of earth before 

 their openings. They are said to live in families of six or eight 

 together, and when at their usual occupation, utter strange and 

 unearthly sounds from their subterranean abode. These noises 

 oft times greatly surprise an individual unacquainted with their 

 habits, while passing over the plain. Sometimes it appears to 

 proceed from directly beneath his feet, and then again it is heard 

 repeated in quick succession from various distances around, so 

 that in a short time from seeing nothing visible, he becomes ex- 

 ceedingly bewildered in endeavoring to obtain a reasonable expla- 

 nation. The natives have given to it the name of Tucutuca, in 

 imitation of this peculiar sound. It is the Ctenomys Brasiliensis 

 of authors, and besides some few other species found on the pam- 

 pas, an allied extinct animal has likewise been procured. 



A singular feature in the landscape, is produced by the habita- 

 tions of the Biscacha, (Lagastomus trichodactylus) which form 



