RODENTIA. 153 
Myororamus, Commer. 
The Couias resemble the Beaver in size,in their four nearly similarly 
composed molars, in their powerful yellow-tinted incisors, and in 
their five-toed feet, the hinder ones of which are palmated; but their 
tail is round and elongated. They are aquatic animals also. One 
only is known, the 
M. coipus ; Mus coipus, Molin., Geoff. Ann. Mus. VI, pl. 
xxxv. (The'Couia.) Which lives in burrows along the banks 
of rivers throughout a great part of South America. The fur, 
which is of a yellowish grey, mixed with down at the root, is 
employed by the hatters like that of the Beaver, and is conse- 
quently an important article of commerce. Thousands of their 
skins are sent to Europe. 
Hystrix, Lin. 
The Porcupines are known at the first glance by the stiff and sharp 
spines, or quills (as they are called) with which they are armed, like 
the Hedgehogs among the Carnaria. Their grinders are four through- 
out, with flat crowns, variously modified by plates of enamel, between 
which are depressed intervals. Their tongue is bristled with spiny 
scales, and their clavicles are too small to rest upon the sternum 
and scapula, being merely suspended by ligaments. They live in 
burrows, and have many of the habits of Rabbits. To their grunt- | 
ing voice, and thick truncated muzzle, are they indebted for being 
compared to the Pig, and for their corresponding French appellation 
of porc-epic. 
Porcurpines, properly so called, 
Have the head more or less convex or vaulted, by the development 
of the bones of the nose. They have four toes before, and five be- 
hind, all armed with stout nails. 
H. cristata, L.; Buff. XII, pl. li and lii. (The Common Por- 
cupine.) Inhabits the south of Italy, Spain, and Sicily; it is 
also found in Barbary. The spines are very long, and annu- 
lated with black and white; a mane composed of long hairs 
occupies the head and neck. The tail is short, and fur- 
nished with hollow truncated tubes, suspended to slender pedi- 
cles, which make a noise when shaken by the animal. The 
chanfrin of the bony head is extremely convex. There are 
other species not very different, but with a less convex head, in 
India and in Africa. 
We separate from the true Porcupines the 
VoL. L—vU 
