IJ2 
RODENTS. 
are primarily distinguished from the last by the toes of the hind-feet being 
reduced to three in number; while the claws on these feet, and to a less degree 
those of the fore-feet also, are relatively longer. The cheek-teeth, with the excep¬ 
tion of the last in the upper jaw, are also distinguished by having only two 
transverse plates of enamel, and their squarer form. 
In its stoutly-built body and sturdy limbs the viscacha, as remarked by the 
late Mr. G. R. Waterhouse, presents a contrast to the delicately-formed chinchillas 
exactly similar to that existing between the squirrels and the marmots; this 
cuvier’s chinchilla (j nat. size). 
difference in form being accompanied by a precisely similar difference in habits, 
the viscachas being purely burrowing rodents. 
In the viscacha the length of the head and body varies from some 19 to 23 
inches; that of the tail being about a third as much again. The ears are rather 
small, and distinctly notched behind, the tail is bushy throughout the greater part 
of its length, and the fur is rather short. The colouring of the fur is somewhat 
striking. Above, the general hue is grey, with some dusky mottlings and black 
markings; while the whole of the under-parts are white or yellowish white. 
From the muzzle a blackish band extends across each cheek; above which is a 
broad white stripe terminating in front of the eyes, while a third narrower dusky 
band crosses the lower part of the forehead. The tail is blackish brown. 
