48 MR. E. T. BENNETT ON THE CHINCHILLIDZ. 
little of the dusky colour of the fur visible on the under surface. The hairs of the tail 
below are entirely of a brownish black ; on the sides they are of two kinds, black and 
white ; as is also the case with the long, rigid, and erectile hairs of the upper surface. 
The very long bristly hairs of the tip are wholly black. On the upper and fore part of 
the head and face, as well as on the limbs, the hair becomes much shorter than on the 
body. 
In form the Chinchilla nearly resembles the Lagotis ; but it is much smaller in size, 
more slender in its limbs, with shorter and more rounded ears, and whiskers less nu- 
merous, shorter, and less rigid. They are of two kinds, black and white, some few 
being black in the lower half and white in the upper: the longest measure about four 
inches. The face and muzzle are very similar to those of Lagotis ; but the large rounded 
open ears measure in height little more than three fourths of the distance between their 
base and the extremity of the muzzle; their sides have none of the parallelism so re- 
markable in Lagotis; and their greatest breadth is little inferior to their length, or 
about an inch and three eighths to an inch and three quarters. In their lobes and 
mode of folding they differ in no material respect from Lagotis, and they are as scantily 
supplied with hair both within and without. The tail has precisely the same character, 
arising from short rigid adpressed hairs below, and long stiff erectile hairs on the upper 
surface, the latter projecting at the tip in a bristly tuft which exceeds the vertebre by 
two inches. 
The anterior and posterior limbs have nearly the same relative proportions to each 
other as those of Lagotis; but the former have an additional toe, corresponding to the 
thumb, which is entirely wanting in Lagotis, and this forms a striking part of the 
generic distinction between the two animals. The corresponding toes are similar in 
their proportions to those of Lagotis, but slenderer, and of greater comparative length 
in their free extent. On the anterior feet the thumb is much shorter than the rest, its 
extremity ranging nearly its own free length behind the base of the adjoining toe. The 
claws are small, flattened, ridged along the middle line, terminating in an obtuse point, 
and concealed by long bristly hairs ; that of the thumb is less strongly ridged than the 
rest. In the palm the basal tubercles nearly resemble those of Lagotis ; and the three 
which are placed at the base of the four outer toes form a curved line, the posterior 
extremities of which are nearly equally advanced. On the under surface the skin is 
deeply marked with strong transverse callous wrinkles, and each toe is furnished with 
a large cushion beneath its tip. The posterior feet have larger claws than the anterior, 
but nearly of the same form, and equally concealed by long hairs, with the exception 
of the inner, which in form and in the bristly comb-like appendage adjoining it, closely 
resembles that of Lagotis. The tubercles of the sole are disposed as in the latter animal; 
and the under surface of the toes is the same in every respect as in the fore feet. 
The beautiful fur of the Chinchilla is still more soft and downy than that of the 
Lagotis, having fewer of the long-black hairs passing through it and projecting beyond 
