MAMMALIA. 
101 
total 20. Head long; eyes large; ears shortish; no cheek 
poaches; fore feet with four toes, and the rudiment of a 
thumb ; hind feet with five toes ; tail long and generally scaly •, 
back covered with shortish flat spines, more or less abundant. 
Echimys hispidus. — The Rough-Haired Echimys. 
Plate XIX. fig. 5. 
Fur brownish-red above, and lighter underneath; head red¬ 
dish ; tail as long as the body, scaly ; hairs of the back very 
rough. From seven to eight inches long. Inhabits South 
America. 
Genus 9.—Myoxus. — Cuvier. 
Generic Character. — Incisors canines none, grinders 
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 tufted in some species ; fur soft. No caecum 
or large intestines. 
Myoxus avellanarius . — The Common Dormouse. 
Plate XIX. fig. 6. 
Fur brownish-yellow above, white underneath; hairs of the 
tail disposed like a feather; tail as long as the body, and flat¬ 
tened horizontally. Inhabits England and various places of 
Europe. 
Genus 10.— Hydromys. — Geoffroy. 
Generic Character. —Incisors no canine teeth, grinders |-| • 
total 12. Crowns of the grinders fiat, 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 and 
round; five toes on all the feet, but the thumb on the fore feet 
very small; hind feet palrnated and united by a membrane ; tail 
