108 EDENTATA. 



43250. The greater number of the bones of the two hind limbs of 



one individual, comprising the femur (imperfect), patella, 

 tibia, fibula, calcaneum, astragalus, and the fifth right 

 metatarsal ; from Buenos Ayres. 



Presented by Senor L. J. Fontana, 1871. 



40069. The right and left tibia, calcaneum, and astragalus ; from 

 Buenos Ayres. The length of the tibia is 0,240, or very 

 nearly the same as in the specimen figured by Owen, op. 

 cit. pi. xx. Purchased, 1866. 



43251. The terminal phalangeal of a third digit ; from Buenos 



Ayres. Presented by Senor L. J. Fontana, 1871. 



40485. An imperfect middle cervical vertebra ; from Uruguay. 



Presented by W. G. Lettsom, Esq., 1867. 



43248. The centrum and part of the arch of a dorsal vertebra ; from 

 Buenos Ayres. Presented by Senor L. J. Fontana, 1871. 



M. 3571. Numerous dermal ossifications, probably belonging either 

 to this or one of the other species of Mylodon ; from Buenos 

 Ayres. No history. 



# * # The Museum also possesses a considerable series of 

 detached bones of the feet from Buenos Ayres, entered in 

 the Eegister under No. 43251, which have not been cata- 

 logued. 



Mylodon lettsomi, Owen '. 



Syn. Pseudolestodon lettsomi, Gervais and Ameghino *. 



This hitherto unfigured species is intermediate in size between M. 

 robustus and M. armatus. It agrees in the position of the upper 

 dental alveoli with the former, but is distinguished by the narrower 

 and more convex palate, the excessive elevation of the inner wall of 

 the hinder dental alveoli, and the narrower interval between the 

 pterygoids. 



Hob. South America (Uruguay and [?] Argentine Republic). 



40486. The cranium (woodcut, fig. 20), wanting both zygomatic 

 (Fig.) arches and all the teeth ; from the Pleistocene of Santa 



Lucia, Uruguay. This is the type specimen ; its length 

 inferiorly is 0,465. 



Presented by W. G. Lettsom, Esq., 1867. 



1 Quoted by H. Gervais and Ameghino in the ' Mammiferes Fossiles de 

 1'Amerique Meridionale,' p. 164 (1880). The name is misspelt, 

 9 Op. cit. 



