NEBRASKA GEOLOGICAL SURVEY 



VOLUME 4, PART II, PLATE 8 



Tctrabelodon willistoiii. a, mandible showing slightly decurved sym- 

 physis; deep groove, and two strong tusks; molars 2, 3, 4; strong ascend- 

 ing rami ; relatively high condyles and coronoids, and a pronounced sig- 

 moid notch, b, top view, c, bottom view. 



