76 



429. The metacarpal bone of the second or index digit. 



430. The metacarpal bone of the third digit. 



431. The metacarpal bone of the fourth digit. 



432. The metacarpal bone of the fifth digit. 



433. The first or proximal phalanx of the pollex. 



434. The distal or ungual phalanx of the same. 



435. The proximal phalanx of the second digit. 



436. The middle phalanx of the same digit. 



437. The distal or ungual phalanx of the same digit. 



438. The proximal phalanx of the middle digit. 



439. The middle phalanx of the same digit. 



440. The ungual phalanx of the same digit. 



441. The proximal half of the right femur of the Mylodon robustus : in this 



bone may be noticed the depression in the posterior part of the head for 

 the attachment of the ligamentum rotundum : the fractured end demon- 

 strates the absence of a medullary cavity. 



The head, supporting the smooth surface presented to the acetabulum, 

 is hemispherical : the articular hemisphere is directed obliquely upwards 

 and inwards, encroached upon at the middle of its posterior margin by 

 the oblong and moderately deep depression for the ligament ; the rest of 

 its circumference is slightly sinuous and anteriorly overhangs the shaft. 

 The upper part of the neck of the femur expands as it passes obliquely 

 from behind forwards to the great trochanter, which scarcely rises above 

 the horizontal line of the neck, and is on a lower level than the head. 

 This trochanter is flattened at its summit and outer side, these surfaces 

 meeting at a right angle : it is produced both forwards and backwards, 

 but chiefly in the latter direction, where it descends like a strong round 



