Dr. Harlan on the Arvicola Ferrugineus. * 285 
ZOOLOGY. 
Ant. 1X.—Description of a New Species of North American 
Quadruped. By Ricuarp Harzay, M. D. Professor of 
Comparative Anatomy to the Philadelphia Musuem, &c. 
- Arvicola Ferrugineus. (nob.) 
Vulgo.—White-bellied Cotton Rat. 
Char. Bopy large, ferruginous, brown above, whitish be- 
neath; fore legs very short and slender ; tail more than half 
the length of the body. 
Dimensions. ‘Total length from the snout to the root of the 
tail 7 inches; length of the tail 4 inches. 
t . Description. Head long; snout tapering ; whiskers white, 
fine, and sparse, some long, others short ; ears rather large, 
broader than long, sparsely hairy within, naked without, an- 
terior borders covered with long hairs—the teeth do not differ 
essentially from those of the 4. hortensis (nob.)* the upper 
molars are rather more compressed in their antero-posterior 
diameter, and the curved lines of enamel on the crowns of the 
inferior assume, In some instances, the form of the Greek epsi- 
lon. Body massive, tapering towards the root of the tail in 
the same manner, though not to the same degree, as in the 
Norway rat; covered with fine long hairs of a dark plumbe- 
ous colour, tipped with brown, and intermixed with black. 
Inferior parts of the body plumbeous white, the hairs being 
plumbeous, tipt with white; tail slender, tapering, covered 
with hair, brown above, whitish beneath; feet grayish, white 
~— 
* Vid. Fauna Americana, p. 138. 
