DEVELOPMENT OF THE SKELETON OF THE TUATARA. 



27 







P. 



Q. 



E. 



S. 



T. 



Adult. 





1. 



? 



u. 



U. 



U. 



U. 



U. 





2. 



9 



u. 



U. 



u. 



V. 



U. 



1— I 



3. 



P. 



u. 



u. 



u. 



u. 



U. 





4. 



P. 



u. 



u. 



u. 



u. 



U. 



't 



5. 



P. 



UA 



u. 



u. 



9 



9 





6. 



P 



UA 



u. 



u. 



— 



F. 





7. 



P. 



UA 



u. 



u. 





F. 





8. 



P. 



t7.+ 



u. 



V. 





F. 





9. 



P. 



U. 



u. 



u. 



F. 



F. 





10. 



P. 



U. 



u. 



■ — . 



F. 



F. 





11. 



P. 



U. 



9 



— 



P. 



F. 





12. 



P. 



U. 



9 



— 



F. 



F. 





la. 



P. 



V. 



. — 



— 



F. 



F. 





14. 



P. 



P. 



— 



— 



— 



F. 





15. 



P. 



P. 



— 



— 



— 



F. 



ji 



16. 



P. 



P. 



— 



— 



. — 



F. 



C 



17. 



P. 



P. 



— 



— 



— 



F. 



^ 



18. 



P. 



P. 



— 





— 



F. 





19. 



P. 



P. 



. — 









F. 





20. 



P. 



P. 



— 





— 



F. 





21. 



P. 



P. 



— 





— 



F. 





22. 



P. 



P. 



— 





— 



F. 





23. 



P. 



P. 



— 





— 



F. 





24. 



P. 



P. 



— 





— 



F. 





25. 



P. 



P. 



— 



— 



— 



F. 



^ 



26. 



P. 



P. 



9 



, 







F. 



§ 



m 



27. 



P. 



P. 



9 



— 



— 



F. 





28. 



P. 



P. 



9 



, 







F. 





29. 



P. 



P. 



9 



. — 



— 



F. 



. 



30. 



P. 



P. 



p. 



p. 



— 



F. 



"Is 

 -a 



31. 



P. 



P. 



Chev. 



Chev. 



Chev. 



Chev.—F. 



g 



32. 



P. 



P. 



Ohev. 



Chev. 



Chev. 



Chev.—F. 



O 



33. 



P. 



P. 



Chev. 



Chev. 



Chev. 



Chev.—F. 





34. 



P. 



P. 



Ohev. 



Chev. 



Chev. 



Cli^v.—F. 





35. 



P. 



P. 



Chev. 



Chev. 



Chev. 



Chev. 







+ 



+ 



+ 



i 



i 



i 



Fig. 5. — Tabular statement of the order of arrangement and succession of intereentra for 



Stages P to T and the adult. 



P. Primary paired intereentra. U. Unpaired intereentra of primary order. — Intereentra absent. 

 F. Secondary intereentra. Chev. Chevrons, t Medially constricted. 



Ribs and Sternum. — Kibs were attributed by Giinther to the segments between and 

 including the fourth prsesternal (cervical) and the second sacral. Discriminating 

 between the osseous rib as a " pleuropophysis " and its unossified ventral portion as a 

 "hsemapophysis," he further distinguished between those vertebrae in which the latter 

 is fully developed as " dorsal " and those in which it is reduced as " cervical " and 

 " lumbar " respectively. 



For the caudal region he describes the presence of "transverse processes" and 



