114 ON PHALANGISTID.E OF THE POST-TERTIARY, BY C. W. DE VIS. 



Pseudochirus the marginal indents are each more or less closed 

 below by an interrupted outer cingulum forming a line of denticles 

 upon the base. 



The teeth of the present fossil have the rows of depressions 

 as distinct semicircular pits — those of the outer series deep 

 infundibuliform excavations of the margin opening upon the 

 summits of the cusps to an extent which gives on the whole the facies 

 of Phascolarctos rather thin that of recent Piiilangers, but not 

 as in Phascolarctos limited externally by a continuous lateral edge. 

 The mesial folds of enamel are two in number and well marked. 



The writer, wishful to avoid the evil of an unnecessary genus, 

 has sought to reconcile these teeth with those of one or other of 

 the ptychodont Phalangers, but seeing how much further they are 

 removed from all recent generic modifications known to him than 

 those are one from another, he is almost fain to admit their claim 

 to a higher than specific rank. The claim, however, will be better 

 considered by some later observer with fuller materials before him. 

 Provisionally the fossil is referred to Pseudochirus as the most 

 likely among living genera to have been transmittad through it, but 

 at the same time a possible affinity with Cuscus on the one hand, 

 and even Phascolarctos on the other, is not to be altogether ignored. 



As to size, the extinct Pseudochirus in view was as large as a 

 Koala (Phascolarctos) and would consequently weigh about 20 lbs. 

 The recent species are comparatively small. 



Phalangista sp. — 



A penultimate lower molar in its segment of the jaw offers no 

 means of distinguishing it from the corresponding tooth in P. 

 vulpina. Until better instructed, we cannot, however, admit this 

 unique claim of the common 'possum to the honours of high 

 antiquity. 



