2. PETROaALE. 71 



Bynoe, its discoverer, and has now disappeared. The species must 

 be very closely allied to P. hrachyotis, and may indeed have been 

 founded upon an individual of that species with the markings un- 

 usually indistinct. 



6. Petrogale concinna. 



Petrogale concinna, Gmild, P. Z. S. 1842, p. 57 ; Gray, List Mamm. 



B. M. p. 92 (1843) ; Gould, Mamm. Austr. ii. pi. xlviii. (animal) 



(1856) ; Krefft, Austr. Vert. p. 11 (1871). 

 Halmaturus concinnus, Schinz, Syn. Mamm. i. p. 565 (1844) ; Wagn. 



Sohr. Sdug. Supp. v. p. 331 (1855). 

 Max;ropus (Heteropus) concinnus, Water h. N. H. Mamm. i. p. 177 



(1846). ^ ^ ' V 



Macropus concinnus, Gieh. S'dug. p. 684 (1869). 

 LriTLB EocK- Wallaby. 



Size very small ; form slender. Fur short, soft, and silky. Under- 

 fur thick, long, and soft, slate-coloured at base, rufous-fawn at 

 tip. General colour rich orange-rufous. Head pale fawn, face- 

 markings obsolete. Ears very short, their backs like the head. 

 Body without any markings, except a very faint trace of the dark 

 patch behind the elbow. Pur of back mainly made up of the under- 

 fur, the rufous tips of which give the general tone to the colour ; the 

 longer hairs, which are black for their basal half or terminal fourth, 

 the other fourth being white, scarcely affecting the general colour. 

 Chin, chest, and beUy white or greyish white. Arms, legs, and feet 

 greyish fawn. Tail pale rufous grey at its base, gradually becoming 

 darker towards the tip, the hairs forming a yellowish-brown, and 

 not a black, terminal pencil. 



Bkull (PI. XII. flg. 4) very small, and quite different in shape 

 from that of the other species. Facial portion comparatively short 

 and brain-case large. Muzzle short, narrow, and pointed, not in- 

 flated. Nasals very narrow in front and enormously broadened 

 behind, their greatest breadth more than three times their least, 

 and more than half their length. Interorbital region broad, flat, 

 paraUel-sided, the edges sharp but not thickened. BuUse slightly 

 swollen. 



Teeth. Incisors (PI. IX. fig. 9) very small and slender ; i.^ about 

 the length .of the edge of i.^ Cheek-teeth, in the only available 

 specimen, oHl square and molariform, five on one side and four on 

 the other. Whether, however, the molar-shaped anterior tooth of 

 the five is a much modified p.*, a milk-p.^ with its successor aborted, 

 or an m.' in a specimen developing five molars on each side *, it is 

 impossible to determine without further specimens for comparison. 



Dimensions, S (imm.). Head and body 350 j hind foot 94 ; ear 27. 

 Skull, see next page. 



Hah. North-west Australia. 



Type in collection. 



J Imm. sk. I , N.W. coast of Australia Sir John Richardson [P.]. 

 "" I Skull. j "■ {Lieut. Emery). (r^/pe of species.) 



* As happens occMionally in Bettongia, see below, p. 105 (footnote). 



