494 PACA AND AGOUTI CHAP. 
arch, by the curving inwards of the bone, which lodges a cavity 
continuous with the mouth. The palate has anteriorly a ridge 
on either side, and is thus divided from the sides of the face in a way 
which is not found! in the allies of Coelogenys. Clavicles are 
present. There are thirteen dorsal vertebrae. The incisors are 
coloured red in front. The animal is South American, and in 
that continent is limited to the Brazilian sub-region. This, the 
best-known species of Paca,is called the Gualilla by the natives of 
Ecuador; in the same district another form 1s met with which the 
natives term Sachacui (signifying Forest Cavy). It 1s very often 
the case that a different native name expresses a real specific 
difference; and to the latter form M. T. Stolzmann has given 
the name of CO. taczanowskii.2 This form, unlike the common 
Paca, which is fond of forests and low-lying ground in the neigh- 
bourhood of water, is alpine in habitat, living upon mountains 
of 6000 to 10,000 feet. It burrows in much the same way as its 
congener, and is greatly sought after as food, its meat possessing 
an “exquisite taste.” It is pursued by dogs, by whose aid one of 
the two entrances to the burrow is guarded, and the creature is 
smoked out and killed with a stick. 
The genus Dasyprocta, containing those Rodents known as 
Agoutis, is divisible into several species, apparently about twelve, 
all of which are, like the Pacas, contined to the Neotropical region. 
They have, however, a much wider range within that region, and 
occur as far north as in Central America and in some of the 
West Indian Islands. They are of rather smaller size than the 
Paca, and are without spots. The colour is of a golden brown in 
some forms, but usually has a freckled, grizzled, greenish kind of 
appearance. The tail is stumpy, the hind-limbs are distinctly 
longer than those of the Paca, and the two lateral toes have dis- 
appeared from the feet—a concomitant as it seems of the Agouti’s 
greater powers of running. The three metatarsals are closely 
pressed together, and the foot is as it were on the way towards 
the highly-modified foot of the Jerboa. The fore-feet are, how- 
ever, five-toed. The clavicle is rudimentary,? whereas it is well 
developed in the Paca. The skull has not the peculiar modifica- 
tions of that of the last-mentioned type. The sternum has seven 
1 There is a faint development of these ridges, but behind the palatine foramina 
in Dasyprocta agutt. 
2 Proc. Zool. Soc. 1885, p. 161. ° Or absent ? 
