202 



Bulletin American Museum of Natural History. [Vol. XXVII, 



Diprotodontidae Pfiascolomyid* 



ascolarctinae MacropodlJae 



Thylacoleon- 



Didelphidae 



MarmoSJ group 



-Tarsipedinae 



Thy lacy nidae 



Perameiidae 



Prono+oryctids 



Notoryctidae 



Didelpliis foup 



Chironectes 

 Fig. 14. Morphogenetic relations of tlie families of the Polyprotodontia and Diprotodontia. 



