134 NAIL-TAILED WALLABY CHAP. 
by Banks. It is said that 15 or even 20 feet are covered at 
a bound, and in bound after bound. But in walking slowly it 
can be readily seen from an inspection of Kangaroos at the 
Zoological Society’s Gardens that the animal does rest upon its 
tail, which with the hind-legs forms a tripod. 
Petrogale with six species comes next to Mucropus, and is 
indeed only to be differentiated from it by the thickly-haired 
and more slender tail, which is not used, as it is sometimes in 
the Kangaroos, as an extra hind-limb. The Rock-Kangaroos live 
among rocks, which they climb, and from which they leap; and 
the tail acts rather as a balancing pole. The most elaborate 
account of the anatomy of Petrogale known to me is by Myr. 
Parsons.’ The dentition as given by Mr. Thomas is I? C9 
Pm 3 M ¢—that of Macropus without the occasionally occurring 
canine of the upper jaw. The osteological characters which 
separate it from Macropus ave quite insignificant. Mr. Parsons 
mentions a wormian bone, “os epilepticum,” at the junction of 
the coronal and sagittal sutures. It was found to occur in two 
out of five skulls examined, and appears not to occur in other 
Kangaroos. The palatine foramina of Petrogale are so large that 
the posterior part of the bone is only a narrow thickened ridge. 
The small intestine of P. vanthopus is 102 inches long, the 
large intestine 44 inches. The caecum has a length of 6 inches, 
and is not sacculated, differing in this from the caecum of 
Macropus major. The best known species are P. zanthopus and 
P. penicillata. The genus is confined to Australia itself, and 
does not enter Tasmania. 
Onychogale includes the so-called “ Nail-tailed Wallabies,” which 
have a thorn at the end of the tail, reminding one of the Lion and 
the Leopard, whose tails have a similar armature. The muffle is 
hairy. Three species are allowed by Mr. Thomas. 
Lagorchestes has, like the last genus, the rhinarium, 7c. that 
part of the nose immediately surrounding the nostrils, hairy 
instead of smooth as in the Kangaroos proper. It is distinguished 
from Onychogale by the absence of the terminal callosity to the 
tail, which is rather short. The name Hare-Kangaroo is given 
to the members of this genus (three species) on account of 
their exceeding fleetness. This genus is limited to Australia 
itself. L. conspicillatus is said to present “a remarkable resem- 
1 Proc. Zool. Soc. 1896, p. 683. 
