PLATE III. 



Fig. 1. Trachodon [I'teropelyx) marginatus, Lambe, inner side of left ramus of lower jaw, showing the 

 teeth ; one-half the natural size. Page 73. 



e, coronoid process ; a, symphyseal surface ; b, inner wall of dental chamber ; c, mandibular 

 groove ; d, foramen. 



Fig. 2. Trachodon (Pteropelyx) selwyni, Lambe, inner surface of teeth of lower jaw, to show succession 

 natural size. Page 69. 



Fig. 3. Grinding surface of teeth of same specimen ; natural size. 



Fig. 4. Scapherpeton tectum, Cope, dorsal vertebra, from the left side ; twice the natural size. Page 31. 



Fig. 5. View from the front, same specimen. 



Fig. 6. Scapherpeton tectum, atlas, front view ; twice the natural size. 



Fig. 7. The same, viewed from behind. 



Fig. 8. The same, side view from the left. 



y, diapophysis ; z, prezygapophysis ; z, postzygapophysis ; s, neural spine ; x, anterior articural 

 cup ; w, neural canal ; v, facet for occipital condyle of skull. 



