412 



unau, shows how widely it differs from the elephant, rhinoceros, and 

 other large ruminants, which have not this bone ; and with the length 

 of the phalanges which carry the nails, prove that this animal employed 

 its fore-feet for the purpose of seizing, and perhaps of climbing. 



The humerus of the megatherium is remarkable for the width of its 

 lower part, produced by the large surface of cristae placed above the con- 

 dyles, and serving for the attachment of muscles, which must have been 

 very considerable, and of course must have given the animal prodigious 

 powers in the fore extremities. This considerable width of the lower 

 extremity of this bone is also found in the ant-eater, which employs his 

 enormous claws to allow him to hang from the branches of trees, or to 

 tear up the solid nests of the termites. In the ant-eater the width is 

 three fifths of the length of the bone, whilst in this animal it is a half) as 

 it is also in the long-tailed manis (Manis tetradactyla). In the rhino- 

 ceros the width is only one third, and in the elephant one fourth of the 

 length. 



The olecranon of this animal is of such a length, as to give consider- 

 able power to the extensors; but, in the sloth, this bone is extremely 

 short. The radius, as in the sloth, turns freely on the cubitus. In the 

 skeleton at Madrid, and in its annexed representation, it must be ob- 

 served that this bone has been reversed in the mounting, the humeral 

 end being placed downwards. 



The hand rested entirely on the ground whilst the animal walked. 

 The visible fingers, armed with claws, are three in number; the two 

 others being hidden under the skin, as in the ai, and as three are in the 

 unau and two-toed ant-eater. The bones of the metacarpus are not 

 joined together, as in the ai. 



The bones of the pelvis differ much from those of the neighbouring 

 genera. Those of the ilium, which are alone preserved in the skeleton 

 at Madrid, forms a large and widely-spread half basin, placed perpen- 

 dicular to the spine, resembling that of the elephant, and still more that 



