1^0 MAMMALIA. 



The Agoutis {CJiJoromys, F. Cuv. ; DaHyprocia, 111.) — 

 Have four toes before and three heliiml, and four grinders aliove and Itelo^v, of nearly equal size, "with 

 flat cro\vns irregularly furro\\cd, and a rounded eoutour, Ufitcljed on llui inner edge of those above, 

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

 Rabbits, which they in some degree represent in tlic Antilbj^ and hot parts of America. 



[Several species have been ascertained, one with only two tors tu the hind-feet. Tliey employ their fure-feet 

 to hold up food to the mouth.] 



The Pacas {delotjemjs-, F. Cuv.; Osteopera, Ilarl.) — 

 y\ith 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 skidl. Their flesh is under:;tood to be 

 fine eating. 



Tliere 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 alhcd to Cavia, jierhaps more approximating to Layonnjs, 

 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 wc have 

 never been able to obtain. "-'■ ^' * 



The Viscacha, described Ijy Azzara, and such as we have seen it flgured, can hardly be otlicr than 

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



[The progress of discovery has realized this expectation of the aulhur, and wc are now acquainted 

 with three subdivisions of these animals, all of ^\hich have four rootless molars aliove 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 Ca\'ies ; but the clavicles are developed, and tlie aspect altogether 

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

 whiskers remarkaldy long and conspicuous, and the tail is always held recurved. These animals hve 

 socially in extensive btuTows. The first subdivision is that of 



The Vi>;cacha {Lagosiomu^, Brookes), — 

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

 them armed witli stout claws adaiited for digging. The cars are of moderate size, and the tail com- 

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

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



The only known species {L. trichodactijhis, Brookes,) is about thr size of a Ilarc, and inhabit.? Chili and Brazil : 

 its iL^erieral 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 Rabbit ; and it seeks 

 its food by night, subsisting wliolly on vegetables : inhabits the level conntr>', and is not esteemed as fuod. This 

 animal is figured iu liritHth's editiim of tlir present wui'k under the name of Diana Marmot. 



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

 The Chinchas {Lagotis, Ben.; Legklium, Meyer) — 



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

 the Chinchilla. 



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

 {L. Cavicriy Ben. ; Lmjiil. pcntr/anuni, iMey.) ; the othci' fiuni tlie Chilian Andes, with shortei" ears, and fur inclining 

 to reddish-brown (L. pa/Z/pcs, Ben.). 



Lastly, 



Thk CiirvcHii.L'V [ChincJiiUa, Ben.; Eriornys, A^ander Ilocvcn ; CaUoi^njs, Gray), — 

 Has a fourth very small internal toe on the hind-foot: cars atnplc ; the internal anditiuT lju.'hi; 

 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. 



