64 LLOYD'S NATURAL HISTORY. 
molar tooth of considerable length, with from two to four 
shallow vertical grooves. 
The Rat-Kangaroos of this genus, as indicated by the small 
size of their hind feet, are less saltatorial in their habits than 
the members of the other genera of the Sub-family, and there 
fore depart more widely from the Wallabies. According to 
Gould, although these Rat-Kangaroos stand as much on their 
hind legs as do the other members of the Sub-family, they run 
in a totally different way, using both fore and hind legs in a 
kind of gallop, and never attempting to kick with the hind feet. 
Externally the three species of the genus are very similar, while 
they present a considerable degree of variation in the structure 
of their skulls. 
I. BROAD-FACED RAT-KANGAROO. POTOROUS PLATYOPS. 
Lypsiprymnus platyops, Gould, Proc. Zool. Soc., 1844, p. 103. 
Potorous platyops, Thomas, Cat. Marsup. Brit. Mus., p. 123 
(1888). 
Characters.—Size very small; naked portion of nose not ex- 
tending backwards along the top of the muzzle; face very 
short and broad ; fur long, coarse, and straight ; hind feet very 
short, long-haired. General colour dark grizzled greyish- 
brown ; under-parts white or greyish-white ; back of ears dark 
brown ; tail black above, dirty white beneath. Length of 
head and body about 14 inches ; of tail 8 inches. 
Distribution.—West Australia. 
Il. GILBERT'S RAT-KANGAROO. POTOROUS GILBERTI. 
LHypsiprymnus gilbertt, Gould, Proc. Zool. Soc., 1841, p. 14. 
Hypsiprymnus micropus, Waterhouse, in Jardine’s Naturalist’s 
Library Mamm. vol. xi., p. 180 (1841). 
Potorous gilberti, Thomas, Cat. Marsup. Brit. Mus., p. 120 
(1888). 
