Mr, Clift on the Megatherium. 447 



Ft. In. Lines. 

 3rd. Length of the third-in-size phalanx 9 ,'3 



Greatest height near the middle 3 2 



Circumference at the same part 9 6 



Breadth at the same part 3 



4th. Length of the fourth-in-size, or smallest phalanx 8 G 



Greatest height near the middle 3 



Circumference at the same part . 9 



Breadth at the same part 2 G 



Pelvis. 



This most enormous and almost disproportioned part of the skeleton difters 

 chiefly from that of the Edentata in the expansion of the ossa ilia*. In other 

 respects it participates in many of the peculiarities which the pelvis exhibits 

 in that tribe. The ischiadic notch^ for example, is converted into a complete 

 foramen on each side, by the anchylosis of the spines of the ischia with the 

 extended transverse processes of the posterior sacral vertebrae. 



The deficiency of the pubis in the specimen at Madrid left room for a sup- 

 position that the pelvis might be open anteriorly, as Cuvier describes it to be 

 in Myrmecophaga didactyla ; but the perfect state of the pelvis in this respect 

 in the present specimen shows that the ossa pubis are completely joined at the 

 symphysis, as in the rest of the Edentate order. 



Its admeasurements are : 



Ft. In. Liiiei. 



From the spinous process of the sacrum to the extreme point of the crestof the ilium 3 



From the extreme point of the ilium to the acetabulum 1 G 



From the extreme point of the crest of the ilium to the anterior part of the sym- 

 physis pubis 3 1- 



From the extreme point of the crest of the ilium to the superior margin of the 



acetabulum 1 9 



The antero-posterior extent of the ilium 1 10 G 



* If it were allowable to contrast the admeasurements of individual parts in two animals m 

 other respects dissimilar, some of those of the Megatherium are so extraordinary, that when com- 

 pared with those of an elephant of eleven feet in height, the latter seem to sink into absolute in- 

 significance. Of these, the pelvis, the femur, and the os calcis afford the most striking examples; 



viz. 



Elephant. Megatherium. 



Ft. In. Ft. In. 



The expansion of the ossa ilia 3 8 5 1 



Breadth of the largest caudal vertebra .... 7 19 



Circumference of middle of femur 10 2 2 



Length of the os calcis 7^ 1 5 



3 M 2 



