AGUTIS AND PA CAS. 



'75 



burrow has been already mentioned ; but, in addition, the viscacha collects every 

 hard object with which it meets. Darwin writes that " around each group of holes 

 many bones of cattle, stones, thistle-stalks, hard clumps of earth, etc., are collected 

 into a heap, which frequently amounts to as much as a wheelbarrow would contain. 

 I was credibly informed that a gentleman, when riding one dark night, dropped his 

 watch ; he returned in the morning, and by searching in the neighbourhood of 

 every viscacha-hole on the line of road, as he expected, soon found it. 



Remains belonging to the same genus as the viscacha are met 



with in the superficial deposits of South America ; while in the older 



formations there occur those of allied extinct genera. One of these extinct rodents 



(Megamys) was the largest member of the order; its size approaching that of 



an ox. 



THE AGUTIS AND PACAS. 

 Family DASYPROCT1DA2. 



The South American Rodents, respectively known by the names of aguti and 

 paca, constitute a small family with the following characteristics. The limbs are 

 of nearly equal lengths, and 

 furnished with hoof - like 

 claws; the tail is short or 

 wanting ; the molar teeth 

 have imperfect roots, and 

 enamel -folds on both sides 

 of the crowns; and the 

 incisor teeth are long. In 

 the skeleton the collar-bones 

 are rudimentary, the palate SKELETON AND SKULL OF 'AGUTI. 



is broad, and the lower jaw 



lacks the distinct ridge on the outer side characteristic of the preceding families. 

 The agutis are elegantly-formed Rodents, with a superficial 

 resemblance to the chevrotains among the Ungulates ; and are char- 

 acterised by their long and slender limbs, and the presence of only three toes on 

 the hind-feet ; the fore-feet, however, having the full number of digits. The hair 

 is coarse, more especially on the hind-quarters, where it becomes longer than 

 elsewhere. The crowns of the molar teeth are rounded ; and when worn exhibit a 

 single lateral fold of enamel, with several islands of the same on their summits. 

 There are several species of aguti inhabiting the greater part of Central and 

 South America as far as Paraguay; and there is one species in the West 

 Indies. The common aguti (Dasyprocta aguti) may be taken as the chief 

 example of the genus, all the members of which are very similar to one 

 another in form and habits. This species, which occurs abundantly in the dense 

 forests of Guiana, Brazil, and Northern Peru, attains a length of from 18 to 20 

 inches, and is of general olive-brown colour. The middle line of the under surface 

 of the body is, however, yellow or whitish ; while the long hairs of the hind- 

 quarters are mostly of a bright orange tint. The feet are pencilled with black and 



