390 



MR. R. I. rOCOCK ON THE EXTERNAL 



but exceeds it in length, although much shorter than the third. 

 The third and fourth are long, thick, and subequal. The ftfth 

 only reaches the distal end of the first phalange of the fourth. 

 The ends of the digits are thick and bluntly rounded, and 

 furnished with nail-lilie claws, which are concealed from the 

 inferior aspect. The sole is marked with a Y-shaped groove, 

 the branches of which run to the margin at the spaces between 

 the second and third and fourth and fifth digits, the upright 



Text-fii?ure 12. 



A. Right hind foot of Ilijocastor coyp^is. 

 r>. ,, fore „ „ „ 



presumably marking the original line between the two elements 

 of the carpal pad. The hind foot has the sole short, only a little 

 longer than in Ctenomys, and, as in that genus, broad in front 

 and narrowed behind. The second, third, fourth, and fifth digits 

 bear much the same relation to each other in length as those of 

 the fore foot, but the hallux is well develo^jed as compared with 

 the pollex and stands well away from the sole. The nails are as 

 in the fore foot, except that on the second digit the nail is claw- 

 like, according to Winge, and projects beyond the tip of the 

 digit, acting, no doubt, as a scratcher. 



