description of plates. 175 



Plate 26. 



Fig. I. Dorsal and lumbar vertebrae of Dimetrodon macrospondylus, showing nearly 

 perfect spines ; No. 1019 University of Chicago. X y^. 



Plate 27. 



Fig. I. Proximal end, femur, Dimctrodoii navajoviais, No. 2285 Am. Mus. Nat. Hist. 

 X I. 



2. Humerus of same. X i. 



3. Lower side of lumbar vertebra of same. X i. 



4. Lateral view of same vertebra. X i. 



5. Two posterior dorsals or lumbars of same. X i. 



6. Fibulare oi Divict7'odo7i incisivus, No. 2275 Am. Mus. Nat. Hist. X i. 



7. TihiaX^ oi Dhiiclrodon 7iavajoviais, No. 2285 Am. Mus. Nat. Hist. X i. 



8. Upper view of vertebrse (?) Tomicosaurus sp., No. 2212 Am. Mus. Nat. 



Hist. X I. 



9. Inner side of anterior end of jaw of same, type, No. 41 10 Am. Mus. Nat. 



Hist. X I. 



10. Lateral view of vertebrse of Embolophorus fritilbis. No. 4010 Am. Mus. Nat. 



Hist. X 2. 



11. A typical caudal of />/w(V;W(;«. X about ^. 



12. A typical caudal of Z)/;«<;//vfl'o«. X about ^. 



13. A typical caudal of Dimetrodon, anterior view, spine complete. X about yi. 



14. Lateral view of an anterior dorsal of 77/fw/>/<r«;-«. X about 3^. 



Plate 28. 



Fig. I. The posterior cervicals or anterior dorsals of Naosaurus claviger, No. 4002 Am. 

 Mus. Nat. Hist. X Yi. 



2. Naosaurus inirabi lis 'sSX.&L VrKXsch.. X about ^3 . 



3. Anterior view of eighth vertebra of Naosaurus microdics, No. 4060 Am. Mus. 



Nat. Hist. X Yi. 



Plate 29. 



Fig. I. Posterior lumbar and sacral region of Naosaurus clavigcr, No. 4002 Am. Mus. 

 Nat. Hist. X Yi- 

 2. A dorsal spine oi Naosaurus microdus (?), No. 4072 Am. Mus. Nat. Hist. X ^3. 



Pl.^te 30. 



Fig. I. Upper surface of interclavicle of Naosaurus clavigcr (?), No. 4103 Am. Mus. 

 Nat. Hist. X >^. 



2. Scapula of right side of Naosaurus clavigcr (?), No. 4146 Am. Mus. Nat. Hist. 



scp, scapula; co, coracoid; pc, procoracoid. X Y^- 



3. Ungual phalanx of Naosaurus. X I. 



Plate 31. 



Fig. I. Outer side of right half of pelvis of Naosaurus clavigcr, No. 4002 Am. Mus. 

 Nat. Hist. //, ilium; pu, pubis; isch, ischium. X y'z. 

 2. YiuraQTMSoi Naosaurus clavigcr, No. 4037 Am. Mus. Nat. Hist. X Y- 



Plate 32. 

 Vertebral column of Naosaurus microdus, No. 4060 Am. Mus. Nat. Hist. X ^. 



