PLATE XL. 



Jurassic Dinosaurs. — Sauropoda. 



Pleuroccelid.e. 



Pape. 

 Fig. 1. Left dentary oone of Pleurocceliis nanus Marsh ; outer view ; one-half 



natural size 183 



a, edentulous margin; «, symphysis. 



Fig. 2. Tooth of I'leurocalus nanus; natural size 183 



a, outer view ; ft, front view ; e, inner view ; d, posterior view. 



FlG. 3. Cervical vertebra of same; side view 183 



3a, transverse section of same vertebra. 



Fig. 4. Dorsal vertebra of same ; side view 184 



Fig. 5. The same vertebra; posterior view 184 



Fig. 6. Sacral vertebra of same ; side view 184 



Fig. 7. The same vertebra ; posterior view 184 



Fig. 8. Caudal vertebra of same ; side view 184 



Fig. 9. The same vertebra ; superior view 184 



Fig. 10. Distal caudal vertebra of same ; side view 184 



Fig. 11. The same vertebra; posterior view 184 



All the figures of vertebrae are one-half natural size. 



a, anterior end of centrum ; c, face for chevron ; /, foramen in centrum ; 

 n, neural canal; p, posterior end of centrum; r, face for rib; «, neural 

 spine. 

 Potomac formation, Maryland. 

 324 



