184 AMPHIBIA. 



* Palatine foramina large, approximated. 



t Mandible with an internal articular process. 



% Orbits centred or posterior. 



1. Mastodonsaurus. 



2. Capitosaurus. 



3. Pachygonia (?). 



4. Trematosaiirus. 



5. Gonioglyptus. 



XX Orbits anterior. 



6. Metopias. 



7. Labyrinthodon. 



tt Mandible without internal articular buttress. 



8. Diadetognathus. 



** Palatine foramina small, distant. 



9. Dasyceps. 



10. Anthracosaurus. 



II. Brachtopina. —Skull i^arabolic ; orbits oval, central or anterior. 



Post-articular process of mandible wanting (I). 



11. Brachyops. 



12. Micropholis. 



13. Rhinosanrus. 



14. Bothriceps. 



III. Chauliodonta. — Skull vaulted, triangular, with large postero- 

 lateral expansions. Lyra consisting of two nearly straight longi- 

 tudinal grooves, continued backwards as ridges. Orbits moder- 

 ate or large, posterior. Temporal depressions passing backwards 

 from the orbits. No post-articular process to the mandible. 

 Teeth unequal, clustered. 



* Teeth tvith large anterior and posterior cutting-edges. 



15. Loxomma. 



** Teeth conical. 



16. Zygosaurus. 



17. Melosaurus. 



IV. Arthroodonta. — Maxillary teeth wanting. Vomerine teeth 

 aggregated. Orbit imperfect. 



18. Batrachiderpeton. 



19. Pteroplax. 



[V. An uncharacterised group for the reception of some or all of the 

 following genera.] 



20. Pholidogaster. 



21. Ichthyerpeton. 



22. Pholiderpeton. 



