568 



ON A SMALL FOSSIL MARSUPIAL ALLIED TO 

 PETAURUS. 



By R. Broom, M.D., B.Sc. 



(Plate XLVi.) 



In the bone breccia deposit in the neighbourhood of the 

 Wombeyan Caves in which I discovered Burramys, I have been 

 fortunate in finding the remains of another small marsupial, also 

 new to science. Of this form I have obtained the greater part 

 of an upper jaw, and an almost complete and two imperfect lower 

 jaws, and also a most important portion of the cranium. 



From the structure of the teeth the form is closely allied to 

 Petanrus and to Gymnohelideus, and though further details may 

 lead to its being included in one or other of these genera, as it 

 presents features distinct from both and also affinities with each 

 I have provisionally placed it in a new genus. 



Pal^opetaurus elegans, g. et sp.nov. 



Dental Formula : — As in Petaurus and Gymnohelideus so far 

 as known. 



Upper Jaiv : — Incisors unknown; canine somewhat conical, less 

 flattened than ^n Petaurus and somewhat shorter proportionately; 

 first premolar smaller than the canine, conical and rather blunt 

 at the apex, single-rooted, antero-posterior length of base very 

 slightly greater than the height, in the unworn tooth possibly 

 less; second premolar (pm.^) with very low crown as in Petaurtis 

 and considerably developed antero-posteriorly, with the main cusp 

 a little in front of the centre of the tooth instead of behind it as 

 in Petaurus^ and with two well developed diverging roots; third 

 premolar (pm.'*) large and triangular, proportionately larger than 

 in PeMurus and Gymnohelideus,* and appreciably higher than 

 the canine; first molar differing from Petaurun in having the two 



* McCoy. Prodr. Zool. Vict. Decade x. PI. xci. (1883). 



