110 EDENTATA. 



Mylodon armatus (P. Gervais '). 



Syn. Lestodon armatus, P. Gervais 2 . 

 Mylodon giganteus, Burmeister 3 . 

 Lestodon giganteus, H. Gervais and Ameghino 4 . 



This species is nearly equal in size to Megatherium americanum ; 

 there is a long diastema between the first and second upper teeth ; 

 the plane of wear of the first tooth in either jaw is very oblique ; 

 the first upper tooth is triangular and large, and the corresponding 

 lower one nearly cylindrical and small. 



Hob. South America (Argentine Republic, Uruguay, and 

 Brazil). 



39377. Fragment of the occipito-parietal region of the cranium ; 

 from the Pleistocene of Uruguay. 



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



The following specimens agree very closely with the limb-bones figured 

 by P. Gervais in the ' Mem. Soc. Geol. France,' ser. 2, vol. ix. 

 pi. xxvi., and are therefore provisionally referred to this species. 



39386. The distal extremity of the right femur ; from Uruguay. 



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



39385. The left tibia ; from Uruguay. This bone is much larger 

 than the tibia of M. robustus, its extreme length being 

 0,326. Presented by D. A. Stoddart, Esq., 1865. 



41619. The imperfect left tibia ; from Rio Grande do Sul, BrazD. 



Presented by T. J. Tennent, Esq., 1869. 



41620. The terminal phalangeal of a median (3rd) digit ; associated 



with the preceding. 



Presented by T. J. Tennent, Esq., 1869. 



M. 1903. The associated left tibia, calcaneum, and astragalus; to- 

 gether with the rnetacarpal and phalangeals of the third 

 digit of the right manus : and the neural arch of a dorsal 

 and the centrum of a lumbar vertebra ; from the Pleisto- 

 cene of the Argentine Republic. 



Presented by Prof. Sir R. Owen, K.C.B., 18S3. 



1 Mammiferes Fossiles de 1'Amerique Meridionale (Castelnau's Voyage), p. 47 

 (1855). Lestodon. 



2 Loc. tit. 



3 An. Mus. Buenos Aires, vol. i. p. 162 (1864-69). 



* Mammiferes Fossiles de 1'Amerique Meridionale, p. 172 (1880). 



