382 HETEROMYS. OCTODONTID&, LONCHERIN#, 
NELSON’s Spiny Mouse. 
Type locality. Pinabete, State of Chiapas, Mexico. 
Genl. Char. Size very large; ears large. Skull long, slender 
superorbital beads faint. 
Color. Above mouse gray, darkest on top of head; upper lip, 
hands, feet, under parts, inner side of fore legs and streak on hind 
leg white; hind feet clouded above; ears without white edges. 
Measurements. Total length, 356; tail vertebre, 195; hind 
fOOE, 43757 
Fam. VI. Octodontidz. The Octodonts. 
This Family has been divided into several subfamilies, only two 
of which, the CAPROMYIN2 and LONCHERINA, are necessary to be 
mentioned as coming within the scope of this work. Save one 
species, the Coypu (Myocastor coypu), yielding the “‘Nutria fur’’ of 
commerce, the members of this family are not generally known 
except to naturalists, and among them, in the New World and on 
certain of its islands, are found the curious Tree Rats of the genus 
Capromys, from which the name of the first of the above-mentioned 
subfamilies is derived; the allied PLAGIODONTIA and various species 
of Spiny Rats of different genera compose the other subfamily 
LoNCHERIN#®. Their trivial names are Hedge-hog or Spiny Rats, 
as many have variously shaped spines mingled with the fur. Some 
are of considerable size, and all have a more or less harsh fur, in some 
instances even bristly. The various species are arboreal, terrestial, 
or aquatic in habits, the Coypu having webbed hind feet and a cylin- 
drical, tapering otter-like tail. The technical characters by which 
these subfamilies are separated exist chiefly in the skull and teeth. 
Subfam. I. Loncherine. 
In the succeeding genera the fur is usually mixed with flattened 
lancet-shaped spines, contracted at the base, and acutely pointed. 
Sometimes they are ridged, and never project beyond the hair. 
Some species are prettily marked in brown and white, but many 
have sombre hues only. Certain members of this subfamily are 
destitute of spines, and so the trivial names for these animals would 
be inappropriate for them, but it will answer well enough for the 
majority of the species found within the limits of this work. 
