84 Prof. Owen on the Reptilian Fossils of South Africa. 



The following figures and letters indicate the same parts in each Plate. 



1. Basi-occipital : 1', inferior processes of ditto. 



2. Ex-occipital : 2', outer process of ditto ; 2", condyloid foramen. 



3. Par-occipital process, abutting against tympanic pedicle. 



4. Sur-occipital. 



5. Basi-sphenoid. 



7. Mastoid. 



8. Parietal. It is perforated in Dicynodon, as in Rhynchocephalm, Iguana, and many 



other recent Lacertians. 



1 1 . Post-frontal. 



12. Mid-frontal. 



13. Vomer. It sends down a strong median longitudinal ridge in Dicynodon. 



14. Pre-frontal. 



15. Nasal. 



16. Lachrymal. 



19. Intermaxillary : 19', palatine ridges of ditto. 



20. Maxillary. 

 20 a. Malar. 



21. Palatine. 



24. Dentary piece of mandible or lower jaw. 



25. Articular piece. 



25 a, Splenial piece. 



26. Angular piece. 



26 a. Coronal piece. 



27. Zygomatic or temporal. 



28. Tympanic. 



c. Canine or maxillary tusk. 



d. Cavity for dental pulp. 

 m. Foramen magnum. 



n. Nasal apertures. 

 0. Orbits. 



p. Palatine or posterior nasal aperture. 



t. Vacuities for the temporal muscles : in PI. V. fig. 2. it marks part of the surface 

 whence the muscles took their origin. 



