1060 



DR. R. BROOM ON THE ORIGIN 



[Dec. 10, 



The relationships of the various groups dealt with above may- 

 be represented by the following diagram : — 



Unkaown Cotylosaurian ancestor. 



Diadectidte (P.) 



GalecMrus (!*■)• 

 ? Dinocephalia 

 (P.). 



Dimetrodon (P.). 

 Therocephalia / Procolophonia (P.). 



(P.). 

 Anomodontia | Mesosauria (P.)- 



(P.). 



PalesoJiatteria 

 (P.). 



03'nodontia 



(T.). \ 



Primitive Mammals 

 (T.). 



Line leading to most 

 Diapsidan reptiles (T.). 



" P." signifies that the types or groups occur in the Permian 

 beds ; " T." that they fii-st occur in Triassic beds. 



Literature referred to. 



1. R. Broom. — " On the Origin of Mammals." Papei-s read at 



the Joint Meeting of the Brit. &, S. Afr. Assoc, in 

 S. Africa, 1905, vol. iii. Johannesburg, 1907. 



2. R. Owen. — " Report on the Rept. Fossils of S. Africa, &c." 



Tr. Geol. Soc. Lond. 1845. 



3. E. D. Cope.—" On the Theromorphous Reptilia." Am. Nat. 



1878. 



4. G. Baur & E. C. Case.—" On the Morphology of the Skull 



of the Pelycosauria and the Origin of Reptiles." Anat. 

 Anz. 1897. 



5. H. F. OsBORN. — " The Reptilian Subclasses Diapsida and 



Synapsida, and the Early Histoiy of the Diaptosauria." 

 Mem. Am. Mus. Nat. Hist., New York, 1903. 



6. G. A. BouLENGER. — " On the Characters and Affinities of the 



Triassic Reptile Telerpeton elginense." P. Z. S. London, 

 1904. 



7. R. Broom. — " On the Use of the Term Anomodontia." Rec. 



Alb. Mus. 1905. 



