n2 MAMMALIA. 



Two species have hcen ascertained, ))Otli (Tom Suutli Africa. 



The Doruiice and Cirn|)liyiires compose tlic .second and hast division of tlic Scinrlda; or Squirrel fainilyj. 

 AVe a})pro\iniate to the Dormice, [bnt with qiiestionahle propriety],— 



The Echymvds {Echijinijs, Geof. ; Loncheres, Illig:.), — 

 Mliicli also have four grinders, bnt diliferently formed ; the snperior consisting of two lamina: bent lik*) 

 a V, the inferior of one bent and one simple lamina. The fur of several species is ""ough, with inter- 

 mixed flattened spines or prickles. They inhabit America. One of them, 



The Golden-tailed Echymyd {Hysirix chrysuros, Sclireb.), is more than double the size of the Brown Rat ; it is 

 a handsome animal, of a bro'^\Ti maroon-colour, the belly white, with a crest of elonjjatfd hairs and a iongitudmal 

 A\liite band on the head ; the tail loni^;, and black, with its posterior half yellow. P'rorn Guiana, Another, 



The Red Echymyd {Erh. nifus ; the Spinous liaf of Azzara), of the size of a Rat, reddish-grey, witli tad shorter 

 than the body, is found in Guiana, Brazil, and Parairuay. It excavates long Bubterrani.^ous burrows. [Tliese 

 species with hairy taih [-ertain to the Xclomys of M. Joui'dan, who restricts the term Eclujinyn to thf following.] 



Others have merely the ordinary kind of hair, more or less rough. 



The most remarkable is £/•/.. daciyltacirs, Geofl"., the Long-toed Echjonyd, wliich is still larger tlian the G<ilden- 

 taited species, and has the two middle toes of the fore-feet double the length of the lateral ones.- its scaly tail is 

 longer thtm the body far yellowish grey ; the hairs on the nose forming a crest directed in front. 



The Mils paradoxus, Thomas {Lin. Trans, xi., IL-trromys, Lesson), apparently diftVrs only from the Echymyds 

 in possessing cheek-pouches. However, nut having seen its teeth, I cannot arrange it. 



[Thb Cercomvds {Ccrcomys, F. Cuv.) — 

 Are closelv related to the preceding, and liavc also four molars surrounded with enamel, which are 

 deeply indented internally, and inclose tliree insulated circlets of enamel near their external border; 

 their form is still more Rat-like, but with the protile of the visage arched ; there are no spines in the 

 fur, and the tail is '.:ing and 'icaly. 

 * )ne speci«.s {C. Orasilicns/s) is tip;ured by M. F. Cuvier m his s:reat work on ^Mammalia]. 



The Hydromyos {IlydromySj Ccof.) — 

 Are '\\ many respects rrlated to the Echymyds externally; but they are distinguislied from all other 

 Rats by their hind-feet, two-thirds of wiiich are palmated : their molars, also, two in number above 

 and below, have a peculiar chaxacter in the crown, which is divided into obliquely quadrangular lobes. 

 the summits of which are hollowcil out like the bowl of a spoon. They are aquatic. 



Several have been sent to Europe from Van Diemen's Land, some with the belly white, others with a fuh'ous 

 belly, but all deep brown above, with a long tail which is black at the base, the distal half white. They are soine- 

 tiTiies double the size of the Brown Rat. //. hydrognsier and U. leucogasier, Geof. [The former is variable, but 

 the latter notwithstanding appears to be another speries.] 



The IIoutias ' Cnpromy^, Desm.) — 

 Have four molars above and I>elow, with flat crowns, tlie enamel of which is folded inward, so as to 

 form three re-entering angles on the external border, and only one on the internal side of those above, 

 and the inverse in the lower ones. Their tail is round, and slightly hairy. Like the Rats, they have 



five toes to their hind feet, and four with the rudiment of a thundj to the anterior; their form is that 

 of Rats as large as a Rabbit or Hare. 



Two [threi'] S]iecies arc known [all frnm the West Indies], which, tn,2;etlier with the Ai^outis, formerly cou.sti- 

 tated the cliicf ,L;ani(; of the indi^^enous inhabitants. Lsoduii pHor/dcs, Say, reftTs to urie of them. ['Ibey at'C 

 not distantly aUied to the Porcupines. It is remarkable that these animals hold up their food (a fusiform rout fur 

 instance) with one foot only to the mouth, resting on the other three. Tliey ascend bushes with facility.] 



TiiE Rats, properly so called, (Mas, Cuv.), — 

 Have three molars to each jaw, the anterior of wliich is the largest [and the posterior smallest], and the 

 crowns of which are (hvidcd into blunt tnlicrcles, which, by attrition, acquire the form of a disc vari- 

 ondy indented ; their tall is long and scaly. These animals are vciy annoying from their fecundity, 

 and the voracity \\ifb wliich they gnaw and dc\our sul^stanccs of c\ery kiuih There are three sitccioa 

 very common in bnu^cs, namely, 

 'i he Ci'iiiniun Aluiisc (,1/. /HKSciiitf-s, Liu).— Knuw u in ah times and all phices. 



