MEGATHERIIDiE. 



109 



39382. Fragment of the left maxilla, showing the alveoli of the 

 three middle teeth ; from the Pleistocene of the Rio Negro, 

 Uruguay. The great elevation of the inner wall of the 

 alveoli is well shown. 



Presented hy D. A. Stoddart, Esq., 1865. 



The following specimens may jperhaps belong to this species. 



19946. The associated right and left femur and the right tibia and 

 fibula ; from Buenos Ayres, Argentine Republic. The 

 femur is larger than the corresponding bone of M. rohustus, 

 and the tibia shorter and thicker, its extreme length being 

 0,196. Purchased 1846. 



Fig. 20. 



Mylodon lettsomi. — Palatal aspect of the cranium ; from the Pleistocene of 

 Uruguay. \. 



19946 a. The right astragalus ; associated with the preceding. 



Purchased, 1846. 



19946 b. The right calcaneum ; associated with the preceding. 



Purchased, 1846. 



19946 C. Three terminal phalangeals ; associated with the preceding. 



Purchased, 1846 



