l^HALAXGERin.E 



157 



Eucalyptus trees, on the buds and tender shoots of which it feeds, 

 though occasionally descending to the ground in the night. 



Extinct Phalangeroids. 



Numerous imperfect remains recently described by De Vis are 

 regarded as indicating large extinct types of Phalangeridce, but 

 further evidence is required before all these determinations can he 

 definitely accepted. Thus part of an upper jaw is provisionally 

 referred to a large species of Pseudochirus, while part of a scapula 

 is made the type of a genus Archizonums which appears to be 



Fig. 50. — The Koala (Phascolarctus cinereus). From Sclater, Proc. Zool. Soc. 18S0, p. 355. 



allied to the former. Another fragmentary scapula is considered to 

 indicate a large Phalanger. Finally, part of a fibula described under 

 the name of Koalemus is regarded as affording evidence of the 

 former existence of a large ancestral form allied to the Koala, and 

 it is suggested that an upper jaw with teeth may belong to the 

 same or an allied type. 



Thylacoleo. 1 — Dentition of adult: i -J, c ^, p -|, I m\ m > total 28. 

 First upper incisor much larger than the others ; canine and first 

 two premolars rudimentary. In the lower jaw the two small 

 anterior premolars are functionless, and often deciduous ; posterior 

 premolars of both jaws formed on the same type as those of Potorous, 

 but relatively much larger ; true molars rudimentary, tubercular. 

 One species, T. carnifex. This animal presents a most anomalous 



1 Owen, in Gervais's Zool. et Pal. frangaises, 1st ed. pt. i. p. 192 (1849-52). 



