RODENTS. 
158 
if a company of gnomes were toiling far down underfoot, beating on their anvils, 
first with strong measured strokes, then with lighter and faster, and with a swing 
and rhythm as if the little men were beating in time to some rude chant unheard 
above the surface.” The tucotucos seem to be somewhat gregarious in their habits, 
as several may be often taken from a single burrow. 
Chili is the home of two species of Rodents known as cururo 
( Spalacopus ), nearly allied to the last, but distinguished by their 
rudimental ears. Somewhat curiously, another nearly related form (Petromys 
typious) is found in South Africa, which differs from its American cousins by the 
harshness of its fur, the shortness of the thumb, the rather bushy tail, and the 
partially rooted molar teeth. 
The Coypu. 
Genus Myopotamus. 
Widely different in its habits from the tucotuco is the coypu (.Myopotamus 
coypu) of South America, which is one of the largest members of the order, 
1|U 
the coypu (1 nat. size). 
attaining a length of from 20 inches to 2 feet, exclusive of the tail. It belongs to a 
group of several genera distinguished from the preceding American examples by the 
very harsh nature of the fur, and depth of the folds of enamel in the half-rooted 
or rootless molars. The coypu itself is characterised by the very large size of its 
incisor teeth; and by the upper molars having two folds of enamel on each side, 
while in those of the lower jaw there are one external and three internal folds. 
The molars are partially rooted, and the last one is larger than either of the others. 
The ears are of moderate size; and the tail, which is scaly, with a thin coating of 
short hairs, is about two-thirds the length of the head and body. Each of the feet 
