PLATE VI. 



LOWER JAW OF TRICERATOPS SULCATUS MARSH. 



(See p. 39.) 

 Plate prepared under the direction of Marsh. 



Specimen No. 4276. U. S. National Museum. 

 Fig. 1. Superior view. 

 Fig. 2. Internal view. 

 Fig. 3. External view. 



ang, Angular; art. articular: cp, coronoid process; d, dentary; s, splenial: sang, surangular. 

 One-sixth natural size. 



210 



