PHALANGERIDE 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 Phalangeride, but 
further evidence is required before all these determinations can be 
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 Archizonurus which appears to be 
Fic, 50.—The Koala (Phascolarctus cinereus). From Selater, Proc. Zool. Soc. 1880, 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: 13, ¢3, p%, m4; 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, 7. carnifer. This animal presents a most anomalous 
1 Owen, in Gervais’s Zool. et Pal. frangaises, Ist ed. pt. i. p. 192 (1849-52). 
