928 ROBERT COLLETT, 



ears are almost white outside; the extremity of tlie tail is greyisli 

 white, whilst the outer half of it in the other speciraens is black. The 

 size of the ears varies considerably in the individuals. 



The skull. 

 A, Length 51,5 mm, breadth 34 mm ; Length of lower jaw 36 mm 

 J3. „ o2,o „ „ oo,o „ „ ,■, ,1 „ ob „ 



0. „ 00,0 ,, „ o4 ,, ,, „ „ „ 04 „ 



U. ,) OD „ ,, OD „ „ „ )) V OO „ 



The skull of this species differs but slightly from that of Pseu- 

 docJiirus. 



The nasalia, are (in the speciraens before me) proportionally 

 shorter, and barely extend forwards further than to above the back 

 margin of i^ (as in the subgenus Hemibelideus; in the typical Pseu- 

 dochiri the nasalia are longer, and extend to * i ). 



The palatina are perforated by two broad and long foramina, 

 which extend to the middle of m 2 , or even (in B) to the front mar- 

 gin of this tooth. 



The bullae osseae are of medium size (almost as in Ps. caudi- 

 volvulus). The external opening into the inferior dental canal is pre- 

 sent on both sides in C and D, on the left side only in B, and is 

 entirely wanting in A. 



The teeth. 



The teeth differ but very little from those of the true Pseudo- 

 chiri. The lower canine is, however, wanting in most of the speciraens; 

 only two of thera have an almost microscopic canine, which scarcely 

 protrudes beyond the raargin of the socket, and thus the species cannot 

 be Said to be entirely without this tooth. Furtherraore there is as 

 good as no trace of the two foremost preraolars in the lower jaw in 

 any of the speciraens, and where they do appear, they are quite ru- 

 dimentary. 



Of the Upper incisors, *3 is the smallest, .and has a cylindrical 

 crown (which has no worn surface on its outer side, as in the genus 

 Petaurus). The central incisors converge at their ends, without, how- 

 ever, touching each other. 



The canine is very small, occasionally not larger than the rudi- 

 mentary p 1 . 



Of the premolars, p^ is rudimentary, or (in B) entirely wanting. 

 It is rather isolated. The two back premolars are present in all; p^ 

 is somewhat sm aller than jp 3 . 



