MAMMALIA. 493 



Genus 8. — Echimys. — Geoffroy 



Generic Character. — Incisory teeth |, no canines, grinders ^-J ; 

 total 20. Head long ; eyes large ; ears shortish ; no cheek 

 pouches ; fore feet with four toes, and the rudiment of a 

 thumb ; hind feet with five toes ; tail long and generally scaly ; 

 back covered virith shortish flat spines, more or less abundant. 



Echimys hispidus — The Rough-Haired Echimys. — Plate 

 XV*. fig. 5 — Fur brownish-red above, and lighter underneath ; 

 head reddish ; tail as long as the body, scaly ; hairs of the back 

 very rough. From seven to eight inches long. Inhabits South 

 America. 



Genus 9. — ]\Iyoxus. — Cuvier. 



Generic Character. — Incisors I, canines none, erinders *-! • 

 total 20. The grinders are divided by transverse bands ; eyes 

 large and prominent; ears large and round; with long mus- 

 tachios ; no cheek pouches ; fore feet with four toes, and the 

 vestige of a thumb ; hind feet with five toes ; tail long, more 

 or less villose, and <ufted in some species ; fur soft. No caecum 

 or large intestines. 



Mijoxus avellanarius. — The Common Dokmouse; — Plate 

 XV*. fig. 6.— Described, vol. II. p. 335. 



Genus 10. — Hydromys. — Geoffroy. 



Generic Character. — Incisors |, no canine teeth, grinders ^ ■ 

 total 12. Crowns of the grinders flat, provided with enamelled 

 ridges in the shape of the figure 8, with two excavations cor- 

 responding with the hollow spaces in that figure; ears small ai.d 

 round ; five toes on all the feet, but the thumb on the fore feet 

 very small ; hind feet palmated and united by a membrane ; tail 

 as long as the body, cylindrical, but pointed at the end, and 

 covered with thick hair. 



Hydromys Coypus.—TaK Coypou Plate XV*. fig. 7 



Fur soft and downy, dark chestnut-brown on the back, red on 

 the flanks, and light-brown on the belly. About two feet long; 

 tail eighteen inches ; hair rather hard. 



Genus 11 — Mus. — Linnaus. 



Generic Character — Incisors Ij, no canine teeth, grinders ^ • 



2t3 



