PERIOD IN QUEENSLAND, BY C. W. DE MS. 



107 



this groove, it may be observed that it deserves to be added to the 

 several signs of affinity between the Wombats and the Phalangers 

 which have attracted notice from systematists. But in the Phalan- 

 gistidse it not merely exists, but is so deeply sunken as to divide the 

 epectosphyre into two angular processes, and confer a characteristic 

 form on this part of the bone — and in none is the peculiarity more 

 emphasized than in the aberrant genus Pbascolarctos in which the 

 separated segments are mo3t produced and enlarged. 



The ectosphyre in Phascolarctos has a semilunate convex 

 surface, sloping obliquely downwards, backwards, and outwards, and 

 defined exteriorly by a roughened depression occupying the internal 

 half of the epectosphyre — the deepest part of the depression forms 

 a groove between the ectosphyre and the anterior segment of the 

 epectosphyre which is produced downwards into an obtuse trihedral 

 pyramid — the depression extends shallowly across three-fourths of 

 the inner base of the posterior segment, the latter is thus imperfectly 

 separated from the ectosphyre in continuity with which it is obliquely 

 produced — this segment is considerably broader and thicker than 

 its fellow. The shaft is subcylindrical, slightly flattened exteriorily, 

 with the flatter surface separated from the rounder by a feeble 

 ridge descending from the postero-interior end of the edge of the 

 posterior surface where it forms a slight angle — distally the shaft 

 suddenly and widely expands to its junction with the epiphysis. 

 The groove dividing the epectosphye is angularly contracted at its 

 base. 



With this the fossil bone has a strong general resemblance in 

 form and arrangement of parts. The following differences seen in 

 Koalemus may be taken as the characters of the genus exhibited 

 in this limited portion of the skeleton. The anterior segment of 

 the epectosphyre produced but very slightly at its anterior angle, 

 forming a roughened triangular plane, impinging by the posterior 

 angle upon the side of the posterior segment. The groove seg- 

 menting the epectosphyre is broadly eoncave at the base. The shaft 

 subquadrate, flattened on the exterior and anterior sides which meet 



