On a new Rock- Wallaby. 681 
the shoulders, lightening on face, fore limbs, and sides to 
whitish grey ; under surface white. Dorsal line distinct, 
from nape to hind back. The usual white patch at the base 
of the ear. Hind limbs and base of tail drab-grey. 
Skull essentially as in true orientalis, but the supraorbital 
ridges comparatively little developed, though the type is 
an old male, the anterior part of the interor bital space with 
rounded adges, and the postorbital processes much reduced. 
Sagittal crest medium.- Teeth as in orientalis, but smaller, 
much smaller than in gymnotis. Canines projecting far 
beyond a line connecting the tips of 2! and 74. 
Dimensions of the type (measured in the flesh) :— 
Head and body 400 mm.; tail (damaged) ; hind foot 55; 
ear 25. 
Skull: greatest length 79; condylo-basal length 76; 
zygomatic breadth 49; nasals 27°5x12°5;  interorbital 
breadth 11°4; tip to tip of postorbital processes 14°25 inter- 
temporal breadth 9° 5; dental length 42 ; diameter of p* 4:3; 
combined length of ms'-3 13-3. 
Hab. Coastal region south of Nassau Range. Type from 
Parimau, Mimika River. Alt. 250!. 
Type. Fully adult male. B.M.no.11.11.11.93. Original 
number 3080. Collected 4th October, 1910, by G. C. Short- 
ridge. Presented by the B.O.U. New Guinea Expedition. 
This animal is so conspicuously smaller than any form of 
Ph. ortentalis inhabiting the mainland of New Guinea that it 
should certainly be distinguished. Its skull is no larger than 
that of the little Ph. breviceps 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 Cuscus, 
which was referred by Jentink to the Ph. gymnotis of the 
Aru Islands. A young specimen possibly referable to 1t was 
obtained by the B.O.U. Expedition at the same time as the 
present form. 
LXXXVI.—A new Lock-Wallaby (Petrogale) from the 
Islands off South Australia. By OLDFIELD ‘THOMAS. 
(Published by permission of the Trustees of the British Museun,) 
Tue British Museum owes to Prof. Wood Jones an example 
of the Rock-Wallaby inhabiting Pearson’s Isles, which are 
part of the Investigator group, in the eastern ee: of the 
Great Australian Bight, about 134° E., 34° 5 
Ann. & Mag. N. He ser. 9. Vol. ix. 44 
