192 



DE. B. A. BENSLET ON^ THE EVOLUTION 



Marmoset and Feramys a beginning of separation of persistent arboreal from terrestrial 

 or semiterrestrial types, just as must have taken place in the original separation of the 

 Dasyuridse from the common ancestors of the Phalangeridse, Peramelidse, and Noto- 

 ryctida?. It is also an interesting fact that the larger members of the Didelphyidfe are 

 conservative in foot-structure exactly as they are in dentition. Both MetacMnis and 

 DideJi^hjs, the larger terminal forms of this incipient radiation, like Feramys, tend to 

 depart from arboreal conditions, but in doing so do not become modified to an appreciably 

 greater extent from the original arboreal type. 



The Phylogenetic Arrangement of the Australian Marsupials. 



In the three preceding sections the attempt has been made to bring together and 

 classify the data at present available as to the origin and sequence of forms in the 

 Australian radiation, by reference to the characters of the dentition and foot-structure, 

 the latter being considered for the most part separately. In the present section a 

 general statement is given of the phylogenetic* conclusions which may be drawn from 

 their combination. 



The accompanying plan, showing the main lines of the radiation, may be consulted as 

 j)reliminary to the more detailed statement of generic and specific relationships given below. 



Dasyurida;. Peramelidae. 



Phalangeridfe. 



MacropodidaR. 



Didelphyid® | ^^-^ 



Cf. closing paragraph of introductory section. 



