130 



NATURAL HISTORY. 



The BROWN SCHIZODON (Schizodonfuscus), which inhabits certain elevated spots in the southern 

 part of the Andes (75 S. lat.), has the enamel folds of the molar teeth meeting in the middle. It 

 is about the size of the common Rat (seven and a half to nine inches long), and has a shortish tail 

 clothed throughout with short hairs. Its fur is dark brown above, dirty yellowish beneath. This 

 animal inhabits grassy places near mountain streams, where the ground is sometimes so undermined 

 by its burrows as to render travelling on horseback very uncomfortable. It is a nocturnal animal, 

 and passes most of its life underground. The valleys it inhabits are covered with snow for at least 

 four months in the year. 



In the TUKOTUKO (Ctenomys brasiliensis) and its congeners, about four of which are 

 known from different parts of South America, one of them extending as far south as the Strait of 

 Magellan, the eyes and ears are very small, and the animal seems to be still more specially adapted 

 to a subterranean mode of life. In these animals the claws are longer than the toes, and those of the 

 hind feet are fringed with a sort of comb formed of bristles. The incisor teeth are very broad. The 

 Tukotuko is about the size of a large Eat, namely, from eight and a half to nine and a half inches long, 

 with the tail from two and a half to three and a half inches. Its name is in imitation of the sound which 

 it constantly emits a sound which rather surprises a stranger when he first hears it, seeing that the 

 animal uttering it is concealed underground. In many places, as in the Argentine Republic, this 

 animal is exceedingly numerous, living generally in sandy soil, but sometimes in damp situations. It 

 makes long burrows not far from the surface, and thus in some places completely undermines the 

 ground. In making these galleries the Tukotuko is engaged in the search for its food, which consists 



chiefly of the roots of plants. According to Azara, it 

 lays up stores of food in its burrows. Its activity is 

 nocturnal. 



The CURURO (Spalacopus Poppigii) has the 

 ears quite rudimentary, and is also organised for a 

 subterranean existence. This and another species in- 

 habit Chili, where they make extensive burrows in the 

 ground, and feed upon the bulboxis and tuberous roots of 

 various plants, large stores of which they collect in their 

 subterranean abodes. These magazines are sought out by 

 the poorer people, and their contents used as food. 



The ROCK RAT (Petromys typicus), although most 

 nearly allied to the preceding species, lives on the opposite 

 side of the Atlantic in the rocky hills of South Africa, 

 especially towards the mouth of the Orange River. It 

 differs from the preceding forms in the harshness of its fur, in which it resembles another sub- 

 family of Octodontidae, in the shortness of its thumbs, which are furnished with a small nail, and 

 in its rather bushy tail. The molars are semi-rooted, with the 

 enamel folds nearly meeting in the middle. The whiskers 

 are of great length, and entirely black. The general colour is 

 reddish-brown, with the head and fore parts greyish, the throat 

 whitish, and the belly pale yellow. The tail is of the colour 

 of the body at the root, with the remainder black. The length 

 of the animal is about seven and a half inches, of the tail 

 from five to five and a half inches. It feeds upon various 

 vegetable substances, and appears to be very fond of the 

 flowers of syngenesious plants, especially a species of groundsel, 

 which it eagerly devours. It forms its retreat among loose 

 stones, or in crevices of the rocks. 



While the Octodontinse may be regarded as specially 

 characteristic of the region of the Andes, the other great 



group of this family is almost exclusively confined to the country east of that great chain, and 

 to some of the West Indian islands. Curiously enough this sub-family also has a single 



DENTITION OF THE ROCK RAT. 



TEETH OF THE SPINY RAT. 



