1422 



(fourteen or fifteen) and slightly oblique ridges. The tail is thickly furred, with 

 the hair longer on the upper than on the lower surface, and somewhat prehensile. 

 In the skull the auditory bulla is generally much swollen, and the unossified spaces 

 in the palate are large. The figured species is a somewhat smaller animal than the 

 common rat kangaroo, and is characterized by the great development of the tuft of 

 hair on the upper surface of the end of the tail, of which the under surface is brown. 

 It inhabits nearly all Australia, but is replaced in Tasmania by the much larger jer- 

 boa kangaroo (B. cuniadus}, in which the tail tuft is scarcely developed. Lesueur's 

 rat kangaroo {B. lesueuri}, of which the skull is figured on p. 1410, is a South and 

 West- Australian species distinguished from the one here figured by the small size 

 of the tail tuft, which is almost always white at the tip. The plain rat kangaroo 



BRUSH-TAILED RAT KANGAROO. 

 (One-fourth natural size.) 



{Caloprymnus campestris} of South Australia, differs from the foregoing by the 

 naked portion of the muzzle extending somewhat less backwardly on the nose, and 

 the absence of any crest or tuft of hair on the tail; and on these and other grounds 

 it is made the type of a distinct genus. 



The largest member of the group is the rufous rat kangaroo (sEpy- 

 prymnus rufescens}, of New South Wales, distinguished from all the 

 others by the partially-hairy muzzle, and the unusually broad and 

 short head; the tail being evenly furred. The permanent premolar tooth in each 

 jaw has a medium number (seven to eight) of vertical ridges, and the skull is char- 

 acterized by the absence of any unossified spaces on the palate, and the unswollen 

 auditory bulla. The head and body of this species may measure as much as twenty 



