On a new Roclc-WaUahy. GSI 



the sliouMoi-5, lio;litenino^ on fjice, fore liinb«, ami sides fo 

 whitish grey ; uiuler surface wliite. Dorsal line distinct, 

 troin nape to hind back. The usual white |)atch ut the base 

 of the ear. Hind limbs and base of t;iii drab-i^rey. 



ISliull essentially as in true orientalis, but the supraorbital 

 ridgos comparatively little developed, though the typo is 

 an old male, the anterior ])art of the interorbital space with 

 rounded edges, and the postorbital processes much reduced. 

 Sagittal crest medium. Teeth as in orientalis, l)ut smaller, 

 much smaller than in qymnoiis. Claniiies [projecting far 

 beyond a line connecting the tips of i' and p'^. 



Dimensions of the ty{)e (measured in the flesh) : — 



Head and body 400 mm. ; tail (damaged); hind foot 56; 

 ear 25. 



Skull : greatest length 79 ; condylo-basal length 7(5 ; 

 zygomatic breadth 49 ; nasals 27*5 X 12-5 ; interorbital 

 breadth 11'4; tip to tip of postorbital processes 14'2 ; inter- 

 temporal breadth 9*5; dental length 42 ; diameter of ^'^ 4*3; 

 combined length of ms^'^ 13'3. 



Hah. Ci»astal region south of Nassau Range. Type from 

 Pariman, Mimika liiver. Alt. 250'. 



T>ipe. Fully adnlt male. B.M. no. 11. 11. 11. 93. Original 

 nunlber 3080. Collected 4th October, 1910, by G. 0. Sliort- 

 ridge. Presented by the B.O.U. New Guinea Expedition. 



This animal is so conspicuously smaller than any form of 

 Ph. orientalis iidiabiting the maiidand of New Guinea that it 

 should certainly be distinguished. Its skull is no larger than 

 that of the little Ph. hreviceps of the Solomon Islands, but 

 has not the remarkably developed supraorbital ridges found 

 in that species. 



In the same region there would seem to be a larger Cuscns, 

 which was referred by Jeutink to the Ph. (jyninotis of the 

 Aru Islands. A young specimen possibly referable to it was 

 obtained by the B.O.U. Ex})edition at the same time as the 

 present form. 



LXXX VI. — A new Rock- Wullahy (Petrogale) from the 



Islands off South Australia. By OldfieLD TllOMAS. 



(Publi-sbed by permission of the Trustees of the Jhrtish Museum.) 



The British JMuseum owes to Prof. Wood Jones an example 

 of the Rock-AVallaby inhabiting Pearson's Isles, which are 

 part of the Investigator group, in the eastern portion of the 

 Great Australian Bight, about 134° E., 34° S. 

 Ann. d- Mag. N. Hist. Ser. 9. Vol. ix. 44 



