HYDROMYS LEUCOGASTER, Geoff.
White-bellied Beaver-Rat.
Hydromys leucogaster, Geoff. Ann. Mus., tom. vi. p. 81. tab. 36. figs. B, C, D?
M. Geoffroy St. Hilaire has given the name of leucogaster to an animal of this genus, and I believe the subject of the accompanying Plate to be the one to which it was applied. The several specimens contained in my collection were obtained on the banks of the Hunter, Clarence, and other rivers traversing the districts lying between the mountain ranges and the sea. They are all similarly marked, and, as will be seen on reference to the Plate, differ very considerably from H. chrysogaster, the tawny white of the under surface occupying the belly only, while the shoulders and upper part of the fore arm are included in the darker colouring of the upper surface. I mention this latter point more particularly, because, were the colouring of the under surface the only difference between the two animals, some persons might suppose that difference to be due to the action of light, which, having abstracted the rich orange colouring, had left the parts thus coloured of a dull or tawny white.
The hinder feet of the two animals also differ, those of H. leucogaster being smaller and of a darker colour than those of H. chrysogaster, and having the toes of the fore feet for half their length from the nails white, a feature I never observed in the latter species. The only character in which they are alike consists in the extent of the white on the tail, which occupies the terminal half in both species.
Head, all the upper surface, shoulders, sides, outer surface of all the limbs, and the portion of the body posterior to them, mingled black and buffy grey, the former hue predominating; face, all the under surface of the body and the inner side of the limbs buffy white; upper surface of the hinder feet deep purplish buffy white; basal half of the tail black, apical half white.
The figures are somewhat less than the size of life.
