174 REVISION OF THE PELYCOSAURIA. 



Plate 20. 

 Restoration oi Dimetrodon incisivus. X about }i. 



Plate 21. 



Fig. I. First intercentrum, atlas; second intercentrum, axis, and third cervical of 

 Di))ictrodo7i gigas. No. 1002 University of Chicago, inter i, preatlantal inter- 

 centrum. a/, atlas ; z«/fr p, second intercentrum. X lA. 



2. Femur of same. X yi . 



3. Two anterior dorsals of same. X yi . 



4. Anterior view of an anterior dorsal of same. X yi. 



5. 6, and 7. Three caudals of same. X }i. 



8. Neural arch of atlas oi Dimetrodon gigas, No. 4034 Am. Mus. Nat. Hist. X i. 



9. Lateral view of an anterior caudal of Dimetrodoii giganhoviogenes. No. 112 



University of Chicago. «, Anterior view of chevron of same. X ^. 



Plate 22. 

 Dimetrodon giganhomogenes, No. 112 University of Chicago. 



Fig. I. Fourth cervical, anterior view. X >2. 



2. Anterior dorsal, anterior view. X Yi. 



3. A posterior dorsal, anterior view. X yi. 



4. A posterior dorsal, near end of series, anterior view. X yi. 



5. An anterior lumbar, anterior view. X ^. 



6. A posterior lumbar, anterior view. X Y^. 



7. Same as figure 2, posterior view. X 3^. 



8. Same as figure i, posterior view. X Y^- 



9. Outer surface of left half of pelvis. X Yi2- 

 ID. Inner surface of same. X 5/,j. 



Plate 23. 



Fig. I. '$)2.zx\xva. oi Dimetrodon doUovianus, 1^0. 114 University of Chicago. X i. 



2. Scapula, coracoid and procoracoid with clavicle of same. X nearly Yi. 



3. Right side of skull of Dimetrodon ineisivus, No. 4001 Am. Mus. Nat. Hist. 



X y,,. Typ& oi Dimetrodon seiniradicat/is. 



Plate 24. 



Fig. I. The anterior cervicals and posterior dorsals of Dimetrodon dolloviatiics, No. 4035 

 Am. Mus. Nat. Hist. X Y^- 

 2. A dorsal vertebra and nearly complete spine of Dimetrodon gigatihofnogettes , 

 No. 112 University of Chicago. X ^3. 



Plate 25. 



Fig. I. Vertebral column of Dimetrodon maerospondyliis, No. 4012 Am. Mus. Nat. 

 Hist. X Y^- 



2. Vertebral column of /7/w(V;(?(/(';; (;^/«.?/(/«w. No. 4062 Am. Mus. Nat. Hist. X ^3. 



3. Lower view of dorsal vertebrae of Dimetrodon maerospondylns, No. 4012 Am. 



Mus. Nat. Hist. To show shape of intercentra. X Y- 



4. Lumbar vertebrae of Dimetrodon maerospondylns, No. 1019 University of 



Chicago. X I. 



5. Inferior view of same vertebrae. X i. 



6. K-s^soi Dimetrodon obtiisidens, 1^0. 1060 University of Chicago. X i. 



