12 



PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



To sum up : The Santa Cruz armadillos differ comparatively little in 

 appearance or in structure from the modern ones, and yet it is apparent 

 that they do not, as a whole, represent the main line of descent which 



IV 



FIG. 5. 

 a, Right pes of Stegotherium tesselatum, x f ; b, left pes of Procutatus lagena, x |. 



ended in the recent genera. That evolution must have taken place in 

 some other region of the South American continent, doubtless the same 

 region as that which gave rise to the true sloths and the anteaters. 



TATUID^. 

 STEGOTHERIUM Ameghino. 



(Plates I-IV.) 



Stegotherium Amegh. ; Enumeracion sistematica de Mam. Fos. de Pata- 

 gonia, 1887, p. 25. 

 Scotceops Amegh. ; Ibid., p. 25. 

 Peltephihis Lydekker, in part; Anales del Museo de La Plata, 1894, T. Ill, 



p. 67. 



In Ameghino's first paper on the Santa Cruz fauna ('87$) he named 

 two genera of edentates, which seemed to have nothing in common. One 

 of these, Scotceops, was described from a fragment of the mandible, which 

 included the alveoli of two teeth and a part of the ascending ramus. The 

 second genus, Stegotherium, was founded upon a number of isolated 



