498 ON THE STRUCTURE OF THE THERIODONT MANDIBLE. [Apr. 19. 



(3) H. G. Seeley, " On the Gomphodontia." Phil. Trans, vol. 186 



(1895) B, p. 1. 



(4) R. Broom, " On some new primitive Theriodonts in the 



S. African Museum." Ann. S. Afr. Mus. vol. iv. pt. 2, 



p. 147. : 



(5) H. Gadow, " On the Modifications of the first and second 



Visceral Arches, with especial reference to the 

 Homologies of the Auditory Ossicles." Phil. Trans, 

 vol. 179(1888). 



(6) J. S. KiXGSLEY, "The Ossicula auditvis." Tufts College 



Studies, no. 6, Feb. 1900. 



(7) E. Gaupp, " Ontogenese und Phylogenese des schallleitenden 



Apparates bei den "Wirbeltieren." Anat, Hefte, Ergeb- 

 nisse, Bd. viii. 1899. 



(8) H. Gadow, " The Evolution of the Auditory Ossicles." Anat. 



Anz. Bd. xix. 1901. 



(9) R. Broom, " On the Fate of the Quadrate in Mammals." Ann. 



& Mag. Nat. Hist. ser. 6, vol. vi. p. 409 (1890). 



EXPLANATION OP PLATE XXXV. 



Fig. 1. Articular region and posterior part of bas€ of skull of Ct/nognathut 



jplatyceps. Nat. size. 

 Figs. 2 & 3. Articular region of Gomphoc/natJms Tcaunemeyeri — from the front. 



Nat. size. 

 Fig. 4. Articulation of mandible of Cynognathus sp. — from below. Nat. size. 

 Fig!5. 5 & 6. Articulation of mandible of Cynognathus sp. — from the outer side 



and in section. Nat. size. 

 7 & 8. Sections of mandible of Trirachodon Icannemeyeri. Nat. size. 

 9 & 10. Sections of mandible of Cynogimtlms sp. About J nat. size. 

 Fig. 11. Tangential section of articulation of mandible of Trirachodon kannemeyeri. 



Nat. size. 



Aug., Angular ; Art., Articular ; M.o., Basi-occipital ; Bent., Dentary ; E.c, Ex- 

 occipital ; F.M., Foramen magnum ; Ju., Jugal ; Ft., Pterygoid ; Qu., Quadrate ; 

 Sg^., Squamosal ; SiWrtMrjr., Surangular ; Ty., Tympanic. 



