120 MAMMALIA. 



The Agoutis (Chloromys, F. Cuv. ; Dasyprocta, 111.) — 

 Have four toes before and three behind, and four grinders above and below, of nearly equal size, with 

 flat crowns irregularly furrowed, and a rounded contour, notched on the inner edge of those above, 

 and the outer of those below. In disposition and the nature of their flesh, they resemble Hares and 

 Rabbits, which they in some degree represent in the Antilles and hot parts of America. 



[Several species have been ascertained, one with only two toes to the hind-feet. They employ their fore-feet 

 to hold up food to the mouth.] 



The Pacas (Cailoyenys, F. Cuv. ; Osteopera, Harl.) — 

 With teeth pretty much resembling those of the Agoutis [and Porcupines], combine a very small 

 additional toe on the inner side of the fore-foot, and two, equally small, on the sides of the hind-foot, 

 which have consequently five in all. Besides this [and in addition to ordinary cheek-pouches], there 

 is a cavity hollowed in each cheek, which dips under the projection of a very large and salient zygo- 

 matic arch, which imparts an extraordinary aspect to the skull. Their flesh is understood to be 

 fine eating. 



There is one species or variety of a fulvous colour, and another brown, both of which are spotted with white 

 (Cavia paca, Lin.). 



Finally, there remains an animal perhaps allied to Cavia, perhaps more approximating to Lagomys, 

 or to the Rats, which we are unable to arrange for want of knowing its dentition, — the Chinchilla of 

 the furriers, the skins of which are imported in immense numbers, but the body we have 

 never been able to obtain. * * * 



The Viscacha, described by Azzara, and such as we have seen it figured, can hardly be other than 

 a large species of Chinchilla, with shorter and coarser fur. 



[The progress of discovery has realized this expectation of the author, and we are now acquainted 

 with three subdivisions of these animals, all of which have four rootless molars above and below, com- 

 posed of alternating transverse layers of enamel and ivory : the form of the cranium and lower jaw 

 indicates considerable affinity with the Cavies ; but the clavicles are developed, and the aspect altogether 

 more Rabbit-like, or rather approximating that of the Pikas ; the eyes are placed far backward, the 

 whiskers remarkably long and conspicuous, and the tail is always held recurved. These animals live 

 socially in extensive burrows. The first subdivision is that of 



The Viscacha (Layostomus, Brookes), — 



In which the fore-feet are furnished with four toes, the hinder with three only, as in the Cavies, all of 

 them armed with stout claws adapted for digging. The ears are of moderate size, and the tail com- 

 paratively short. Their three anterior molars of the upper jaw consist each of two double layers, and 

 the last of three ; the lower of two each throughout. 



The only known species (L. trichodaclylus, Brookes,) is about the size of a Hare, and inhabits Chili and Brazil : 

 its general colour is greyish, the fur of two sorts, one entirely white, and the other, which is coarser, black, 

 except at the base ; the under parts white. Its motions are quick, and resemble those of a Rahbit ; and it seeks 

 its food by night, subsisting wholly on vegetables : inhabits the level country, and is not esteemed as food. This 

 animal is figured in Griffith's edition of the present work under the name of Diana Marmot. 



The others are mountain animals, which frequent rocky places near the snow-line. 

 The Chinchas (Lagotis, Ben. ; Legidium, Meyer) — 

 Scarcely differ from the Viscacha except in having four toes to each foot, and a long bristly tail, as in 

 the Chinchilla. 



Two species are known ; the first with long Rabbit-like ears, and greyish fur, from the Peruvian Andes 

 (L. Cuvieri, Ben. ; Legid. peruvianum, Mey.) ; the other from the Chilian Andes, with shorter ears, and fur inclining 

 to reddish-brown (L. pallipes, Ben.). 



Lastly, 



The Chinchilla (Chinchilla, Ben. ; Eriomys, Vander Hoeven ; Caliomys, Gray), — 

 Has a fourth very small internal toe on the hind-foot : ears ample ; the internal auditory bulla? 

 remarkably capacious, appearing on the upper part of the skull. Each of the upper molars has 

 three alternate layers of enamel and ivory, the inferior only two. 



