A description of the genus dimetrodon, cope. 61 



Fig. 



1. 



Fig. 



2. 



Fig. 



3. 



Fig. 



4. 



Fig. 



5. 



Fig. 



6. 



Fig. 



7. 



Fig. 



8. 



Fig. 



9. 



Fig. 



10. 



Fig. 



11. 



Fig. 



12. 



Fig. 



13. 



Fig. 



14. 



Fig. 



15. 



Fig. 



16. 



Fig. 



17. 



Fig. 



18. 



Explanation of the Plates. 

 Plate I- — Dimetrodon incisivus Cope. 



All figures £ natural size. 



Premaxillary = pm. 



Nasal and maxillary = n. and m. 



Prefrontal = prf. 



Frontal = f. 



Parietal = p. 



Jugal=j. 



Postorbital = po. 



Suspensorial 

 region. 



Upper view, quadrate = q.; quadratojugal = qj. 



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

 _ Lower view. 

 Cranial region ; upper view. 

 Cranial region ; lower view. 

 Basisphenoid ; lateral view. 

 Basisphenoid ; lower view. 

 Pterygoid ; external view. 

 Pterygoid ; lower view. 

 Dentary = d. 

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



Plate II — Dimetrodon incisivus Cope. 



Fig. 19. First intercentrum. 



a, lower ; b, posterior view. £. 



Fig. 20. Centrum of atlas, second intercentrum "and axis. 



Fig. 21. Seventh cervical ; lateral view. £. 



Fig. 22. Seventh cervical ; anterior view. ^. 



Fig. 23. Sixth dorsal ; anterior view. £. 



Fig. 24. Sixth dorsal ; lateral view. £. 



Fig. 25. Tenth dorsal ; lateral view. £. 



Fig. 26. Tenth dorsal ; anterior view. £. 



Fig. 27. Three anterior caudals ; lateral view. ^. 



Fig. 28. An anterior caudal ; anterior view. £. 



Fig. 29. The same ; lower view. £. 



