HAPLODONTIM3— 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 nearlj 

 parallel axes, though the lateral ones, and especially the inner one, stand a 

 Utile away from the line of the other three. These lastaremuch 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 Lagomijs 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. 



These staring hairs are specially noticeable on the limbs and under parts gen- 



36 M 



