572 



REFTILIA 



[CH. 



auditory capsule. The pterygoid process is completely ossified by 

 the pterygoid bone behind and the palatine in front. 



A curious bone, characteristic of many of the Lacertilia, is the 

 epipterygoid or columella cranii, which runs from the pterygoid 



-32 



FIG. 281. A. lateral view, and B. longitudinal section of the skull of a Lizard, 

 Varanus varius x f . 



1. Premaxilla. 2. Maxilla. 3. Nasal. 4. Lateral ethmoid. 5. Supra- 

 orbital. 6. Lachrymal. 7. Frontal. 8. Postfrontal. 9. Prefrontal. 

 10. Basisphenoid. 11. Pro-otic. 12. Epi-otic. 13. Pterygoid. 



14. Epipterygoid (columella cranii). 15. Jugal. 16. Transverse bone. 

 17. Parasphenoid. 18. Quadrate. 19. Parietal. 20. Squamosal. 

 21. Supratemporal. 22. Exoccipital. 23. Dentary. 24. Splenial. 

 25. Supra-angular. 26. Angular. 27. Coronoid. 28. Articular. 

 29. Vomer. 30. Basi-occipital. 31. Orbitosphenoid. 



vertically up to the parietal. This bone is however found only in 

 some Lacertilia, not in Reptiles generally. 



The two pterygoid bones, instead of arching outwards, as in 



