CLASSIFICATION OF VERTEBRATA 40 



2. Sub-CLASS METATHEEIA, Huxley, s. MAR- 

 SUPIALIA, Illiger, s. DIDELPHIA, de Blainville 



Viviparous, with marsupium ; without chorion ; with epi- 

 pubic or marsupial bones. 



Coracoids reduced, not reaching the sternum. 



Males at least without cloaca. 



1. Order Polyprotodontia, Owen. Dentition complete ; 

 lower jaw with three or four pairs of incisors. Carnivorous ; 

 without caecum. Since the Triassic epoch. 



1. Sub -order ?PEOTODONTA, Osborn. Dromatherium. 

 Upper Trias, Carolina. 



2. Sub-order ?TEICONODONTA, Osborn. Amphilestes 

 and Phascolotherium, Oolite ; Triconodon, upper Jurassic, 

 England. 



3. Sub-order TRITUBEECULATA, Cope. 

 Amphitheriidae. Jurassic, Cretaceous, England. 

 Amblotheriidae. Amblotherium and Dryolestes. Jurassic 



and Cretaceous of North America. 



Myrmecobiidae. Myrmecobius fasciatus. West Australia. 



Pemmelidae. Perameles, Chaeropus. Australia. 



Dasyuridae. Dasyurus, Thylacinus. Australia, since the 

 Plistocene. 



Doubtful relatives in Tertiary, Patagonia. 



Notorydidae. Notoryctes typhlops. Central Australia. 



DidelpTiyidae. Since the Eocene in America and Europe. 



Eecent : 



Didelphys. N. and S. America. 

 Chironectes. S. America, Chile. 



2. Order Diprotodontia, Owen. Lower jaw with one pair 

 of incisors. 



Canines weak or absent. Herbivorous, with caecum. 



Since the Mid-Tertiary epoch in South America ; since the 

 Plistocene in Australia. 



JZpanorthidae. Epanorthus. Mid-Tertiary, Patagonia. 

 Caenolestes. Ecuador and Columbia. 



Pkalangistidae. Phalangista, Petaurus, Phascolarctos, in 

 Australia and Papuasia. 



