RODENTIA. ] 37 



time the mouse, apparently exhausted with its exertions, dropped 

 dead on the floor. 



M. leucopiis, (Gr. Isvxog, leukos, white; novs,pous, foot.) 

 This little animal is of a brownish color above ; the feet and 

 all beneath, white; the ears large; the tail hairy and as long 

 as the body. The whole length is six inches. The colors and 

 proportions give this mouse a delicate and beautiful appearance. 

 Like the Deer mouse, it is, from its agile, jumping movement^ 

 called the "Jumping Mouse." It feeds on grains and grasses. 

 M. messorius, (Lat. messis, a harvest.) This is the smallest 

 and one of the most beautiful of the mammalia, called the HAR- 

 VEST MOUSE. It is scarcely half the size of the common mouse. 

 The color is of a reddish brown or squirrel-like aspect above ; 

 the under parts white ; its eyes are dark ; its action lively. In 

 winter it lives under ground in burrows, but it breeds in grassy 

 compact nests of the size of a cricket-ball, like those of a bird, 

 made among the stalks of the standing corn, and supported on 

 two or three straws. The principal food of the harvest mouse 

 is corn ; but it is also fond of insects. 



Arvicola, (Lat. arva, corn-fields ; co/o, I inhabit.) This genus 

 includes many species known under the names of FIELD MICE 

 arid FIELD RATS, differing from the mice proper in the structure 

 of their teeth, and the length and hairy covering of the tail. 



A. amphibius is the Water Rat common on the banks of riv- 

 ers, brooks, &c. 



Geomys, (Gr. 7*7, ge, earth ; <wv?, mus, mouse.) POUCHED RAT, 

 SAND RAT. (See Plate V., fig 3.) 



Of this genus there are several species, having eyes small and 

 far apart ; small ears ; ten molars above and ten below ; large 

 and pendulous cheek pouches, opening, (according to Audubon,) 

 outside of the mouth, and extending in some species along the neck 

 to near the shoulders. These poaches are cold to the touch and 

 of an oblong form when distended. This animal has been seen 

 " when in the act of emptying its pouches into its paws like 

 a Marmot Squirrel, and squeezing its sacs against the breast with 

 its fore paws." 



7th FAMILY. 



Caviada of Tropical America. 



The Cavies seem to hold a middle rank between the Mouse 

 and the Rabbit. 



Hydrochoerus, (Gr. 'vdu^j hudor, water ; ZOIQOS, choiros, a hog.) 

 CAPYBARA, or WATER-HOG, of South America. 



This animal attains to the size of a hog of two years old ; 

 lives on vegetables, sugar-cane and fish. To procure the latter, 



