THE ROCK-WALLABIES. 43 
The Rock-Wallabies are confined to the mainland of Aus- 
tralia, on which they are generally distributed, but are un- 
known in Tasmania. Although closely allied to the true 
Wallabies, their habits are markedly distinct, the Rock-Walla- 
bies frequenting rugged rocky districts instead of the open 
plains. In such situations they leap and climb with remark- 
able agility, their long bushy tails being used solely to help 
in balancing the body, and never being employed as an ad- 
ditional support. Consequently the tail has not the same 
strength and thickness as in their plain-haunting cousins. 
I. BRUSH-TAILED ROCK-WALLABY. PETROGALE PENICILLATA, 
Kangurus penicillatus, Gray, in Griffith's Animal Kingdom, 
vol. v., p. 204 (1827). 
Macropus penicillatus, Bennett, Proc. Zool. Soc., 1835, p. 1. 
Petrogale penicillata, Gray, Mag. Nat. Hist., vol. i, p. 583 
(1837); Thomas, Cat. Marsup. Brit. Mus., p. 66 (1888). 
_ Halmaturus penicillatus, Wagner, in Schreber’s Saugeth. Suppl., 
vol. iii., p. 126 (1843). 
| (Plate VI.) 
Characters,—Size large; form stout and heavy ; fur long, 
thick, and coarse. General colour dull brown, tending to 
rufous on the rump; chin and chest pale grey; remainder of 
under-parts brown tinged with yellow, becoming yellowish- 
rufous posteriorly. Whisker-mark and cheek-stripe ill-defined ; 
a black streak on the back of the head, not extending to neck. 
| Ears short, yellow internally and on the posterior margin, else- 
where grey at base and black terminally; a black and often 
| inconspicuous mark behind the shoulder, followed by a pale 
grey one. Legs brown or rufous ; toes black ; tail long, more 
(or less bushy, rufous for the basal three or four inches, else- 
| where black, save sometimes the extreme tip, which may be 
| 
