526 THE MECHANICAL FUNCTIONS. 



shape than an ordinary scapula : the humerus, 

 on the contrary, is thick and square, and the cla- 

 vicle is short and broad. The radius and the 

 ulna are distinct from each other ; the hand is 

 very large and expanded; the palms being 

 turned outwards and backwards, and its lower 

 margin being fashioned into a sharp cutting 

 edge. The carpal bones and the phalanges of 

 the fingers are very much compressed ; but they 

 are furnished with large nails, which compose 

 more than half the hands; and they are ex- 

 pressly constructed for digging, being long, 

 broad, and sharp at the extremities. The ster- 

 num has a large middle crest, and is prolonged 

 at its extremity into a sharp process, having the 

 figure of a ploughshare, thus affording an exten- 

 sive surface of attachment for the large pectoral 

 muscles, from which the limb derives its princi- 

 pal force. The head terminates in front by a 

 pointed nose, which is armed at its extremity 

 with a small bone, intended to assist in pene- 

 trating through the ground. 



While all this attention has been paid to the 

 developement of the anterior part of the body 

 to which these instruments specially contrived 

 for burrowing are affixed, the hinder part is com- 

 paratively feeble, and appears stinted in its 

 growth, and curtailed of its fair proportions. 

 The pelvis is exceedingly diminutive, being re- 

 duced to a slender sacrum ; and it is thrown far 



