TAB. XIII. 

 Ophidia.— Recent and Fossil Ophidian Vertebrae; nat. size. 



Fig. 



1 — 4. Vertebrae from the middle of the body of a Python Sebce, twenty feet in length. 



2/ 3'. A rib of the same Python. 



3". Section of the proximal end of a rib of the same Python, showing the medullary 

 cavity. 



5 — 8. Vertebrae from the middle of the body of the Palceophis typhous. 



9 — 12. Corresponding vertebrae of a rattle-snake. (Crotalm.) 

 13 — 16. Corresponding vertebrae of a hooded-snake. {Naja.) 

 17 — 20. Corresponding vertebrae of a harmless snake. {Coluber elaphus.) 

 21 — 24. Corresponding vertebrae of an African Eryx. 

 25 — 28. Corresponding vertebrae of a sea-snake. (Hydras bicolor.) 

 29 — 32. Corresponding vertebrae of Paleryx rhombifer. 

 33 — 36. Corresponding vertebrae of an Iguana. 

 37 — 38. Corresponding vertebrae of Paleryx depressus. 



