AGUTIS AND DA 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. 
Fossil Forms. 
SKELETON AND SKULL OF AGUTI, 
The Agutis and Pacas. 
Family Dasyproctidaz. 
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 
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 liind-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 (Dasygyrocta 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 
Agutis. 
