A DESCRIPTION OF THE GENUS DIMETRODON, COPE. 



61 



Explanation of the Plates. 



Plate I- — Dimelrodon incisivus Cope. 



All figures J natural size. 



Fig. 

 Fig. 

 Fig. 8. 



Fig. 4. 

 Fig. 5. 

 Fig. 0. 

 Pig 



1. Premaxillary sa pm. 



2. Nasal and maxillary = n. and in. 

 Prefrontal prf. 

 Frontal f. 

 Parietal = p. 

 Jugal = j. 



7. Postorbital = po. 



Fig. 8. 

 Fig. 9. 

 Fig. K). 

 Fig. 11. 

 Pig. 12. 

 Fig. 13. 

 Fig. 14. 

 Fig. 15. 

 Fig. 16. 

 Fig. 17. 

 Fig. 18. 



Suspensorial 



region. 



Upper view, quadrate q.j quad ratoju gal = qj. 



Outer view, squamosal =s sq. ; prosquamosal — psq. 



Lower view. 

 Cranial region ; upper view. 

 Cranial region ; lower view. 

 Basisphenoid ; lateral view. 

 Baslsphenoid ; lower view. 

 Pterygoid ; external view. 

 Pterygoid ; lower view. 

 Oentary = d. 

 Articular region ; articular = a.; angular portion of articular — an. 



Plate II- — Dimetrodon incisivus Cope. 



Fig. 19. 



Pig, 



20. 



Pig. 



21. 



Fig. 



22. 



Fig. 



38. 



Fig. 



24. 



Pig. 



25. 



Fig. 



20. 



Pig. 



27. 



Fig. 



28. 



Fig. 



29. 



First, interccntrum. 



a, lower ; b, posterior view. L 



Centrum of atlas, second intercentrum and axis. £. 



Seventh cervical ; lateral view. £. 



Sovontli cervical ; anterior view. J. 



Sixth dorsal ; anterior view. |. 



Sixth dorsal ; lateral view. J. 



Tenth dorsal ; lateral view. ^. 



Tenth dorsal ; anterior view. ^. 



Three anterior caudals ; lateral view. J. 



An anterior caudal ; anterior view. J. 



The same ; lower view. J. 



