HAPLODONTIDA—EXTERNAL CHARACTERS OF H. RUFUS. 561 
is entirely enclosed in the common integument of the body, which even de- 
scends a little below the knee. The bulging, compressed crus tapers rapidly 
to the ankle, where the ordinary pelage of the body is arrested, the instep 
and tops of the toes being clothed with very short, adpressed, colorless hairs, 
and hence appearing almost naked, as, indeed, they have sometimes been 
described. But the clothing is uniform and complete, and nearly as heavy 
as that on the back of the hands. The foot is rather longer than the hand, 
even including the claws, which are so highly developed on the fore limb. 
The axis of the foot appears to be nearly at right angles with that of the leg 
in ordinary postures of the animal; the heel is prominent, and the whole 
sole is evidently applied to the ground in walking. Such plantigrade char- 
acter of the hind feet is indicated by the strong flattening of the sole to the 
very heel; and its complete nakedness The sole is perfectly smooth, with 
a moderate number of irregular lines of impression, more numerous anteriorly 
than toward the heel. There are six prominent tubercles on the sole; four 
at the bases of the digits, and two, side by side, about half-way to the heel. 
Of the anterior tubercles, one is common to the 3d and 4th digits, and three 
others are respectively proper to the 1st, 2d, and 5th digits. Of the posterior 
pair of tubercles, a larger one, conical and very prominent, is situated on the 
inner side of the sole; the other, much less conspicuous, is also further re- 
moved from the edge of the foot. There are five perfect digits, with nearly 
parallel axes, though the lateral ones, and especially the inner one, stand a 
little away from the line of the other three. These last are much the longest, 
and of approximately equal lengths. The end of the claw of the 5th only. 
attains the base of the 4th claw; that of the 1st does not quite reach the 
base of the 2d. The claws of all the digits are much alike, and peculiar in 
no respect. 
The tail is a mere stump, shorter than the foot; it is cylindrical, thickly 
clothed with pelage like that of the body, and the terminal pencil of hairs 
equals in length that portion of the vertebrae which projects beyond the but- 
tocks. Short as this member is, it is not “‘concealed” in any of the specimens 
before me. It is much more conspicuous than that of Lagomys princeps. 
The general pelage has been likened to that of a rabbit when out of 
season; it seems, however, to be coarser, owing to the number of long, stiff, 
almost bristly hairs which are mixed with the dense, soft, woolly under fur. 
gen- 
These staring hairs are specially noticeable on the limbs and under parts g 
36 M 
