BIG BADLANDS OF SOUTH DAKOTA. 



485 



outside the line of the other teeth (Fig. 17). The posterior mental 

 processes, on the other hand, are long, directed forward and of 

 uniform width. 



Fig. 14. Scaptohyus altidens gen. et sp. nov. Holotype, No. 11161. Lower 

 jaws seen from in front, about 0.17 natural size. Drawn from photograph 

 and the specimen. 



A fragment of the distal end of the left cheek flange shown in 

 Fig. 12 has the thin front margin concave to the point of greatest 

 expansion, beyond which it extends backward in a straight line and 

 rapidly thickens to the distal end, where the maximum thickness is 

 36 mm. What little remains of the thin posterior margin is also 



Fig. 15. Scaptohyus altidens gen. et sp. nov. Holotype, No. 11161. Side 

 view of left half of lower jaw, about 0.15 natural size. Drawn from photo- 

 graph and the specimen. 



