Plate VI. 



Figures 1-6. — Seven anterior cervical vertebrae of the type of P. ingens Marsh, No. 1175; 

 seen from the left side ; slightly restored, x 0.50 



Figure 1. — Atlas and axis. 

 Figure 2. — Third cervical. 

 Figure 3. — Fourth cervical. 

 Figure 4. — Fifth cervical. 

 Figure 5. — Sixth cervical. 

 Figure 6. — Seventh cervical. 



Figure 7. — Seventh cervical vertebra of Pteranodon sp., No. 2692 ; seen trom the left side. 

 x0.66 



Figure 8. — Eighth cervical vertebra of the same individual ; seen from the left side ; 

 showing rib. x 0.66 



Figure 9. — Ninth cervical vertebra of the same individual ; seen from the left side, 

 x 0.66 



Figure 10. — Eighth cervical vertebra of the same individual ; anterior view, x 0.66 



Figure 11. — Atlas and axis of the type of P. longiceps Marsh, No. 1177; seen from the 

 left side, x 1.0 



Figure 12. — Atlas and axis of the type of P. ingens Marsh, No. 1175 ; seen from the rear. 

 x 0.66 



Figure 13. — Fourth cervical vertebra of the type of P. ingens Marsh, No. 1175: anterior 

 view, x 0.50 



Figure 14. — The same specimen ; posterior view, x 0.50 



Figure 15. — Right rib of the ninth cervical vertebra of the type of P. ingens Marsh, 

 No. 1175; posterior view, x 0.50 



Figure 16. — Right rib of the ninth cervical vertebra of Pteranodon sp., No. 2692 : anterior 

 view, x 0.66 



Figures 17-20. — Four free dorsal vertebras of Pteranodon sp., No. 2616; seen from the 

 left side ; slightly restored, x 0.66 



Figure 21. — First free dorsal vertebra of the foregoing series; anterior view, x 0.66 



Figure 22. — The same vertebra ; posterior view, x 0.(56 



Figure 23. — Four caudal vertebrae of Pteranodon sp., No. 2546; seen from below, x 0.66 



