HYDROMYS. 101 
1. Hypromys curysoGastEr, Geoffroy (1805). 
Kastern Water Rat. 
Fig. 4. 
Fig. 4.—Under surface of skull to show palate and dentition (natural 
size). a, Upper molars, enlarged. b, Side view of same, enlarged. 
Fig. 5.—Side view of skull and ramus (natural size). 
Fig. 6.—Lower jaw. 
Head, ears, back, outer surface of hind limbs, the body behind 
them, and the root of the tail grizzled black and buff, the former 
color predominating ; sides of face and body, the entire under 
surface, and the inner side of the limbs rich deep reddish-orange 
or buffy-white ; outer surface of arms deep brown ; upper surface 
of hind feet pale glaucous-buff, passing into brown on the tips of 
the toes ; basal half of tail black, apical half white. 
Habitat.—Eastern Australia and Tasmania, ranging at least 
as far northwards as the Herbert River District. 
References.—Gould, Mamm. Austr. iil. pls. xxiv. (H. chryso- 
gaster) and xxvi. (H. leucogaster); Thomas, Proc. Zool. Soc. 1889, 
p. 247, pl. xxix. fig. 7 (anterior zygoma-root). 
Note.—The two forms here mentioned, though for many years 
kept separate as distinct species, are now generally allowed to 
be mere color varieties of one species. 
