494 PACA AND AGOUTI 



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 l 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 is met with which the 

 natives term Sachacui (signifying Forest Cavy). It is 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 C. taczanowskii? 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, confined 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, 3 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 aguti. 



2 Proc. Zool. Soc. 1885, p. 161. s Or absent ? 



