1867.] DR. J. E. GRAY ON AUSTRALASIAN RATS. 597 



3. Notes on the Variegated or Yellow-tailed Rats of Austra- 

 lasia. By Dr. J. E. Gray, F.R.S., V.P.Z.S., F.L.S., &c. 



At the Meeting of this Society for May 8, 1866, I described a 

 large Rat with a black and yellow tail from North Australia, under 

 the name of Mm* macropus*. We have since received another spe- 

 cimen of this Rat from Cape York ; and Mr. Gerard Kreflft has 

 informed me in a note that it is evidently the animal which he has 

 proposed to call Hapalotis caudhnacidata in a paper on Australian 

 animals recently sent to this Society f, 



I may add to the former description that the cutting-teeth are 

 bright orange-yellow in front ; the front side of the upper one is 

 broad, flat, and smooth, with a narrow, slightly shelving margin 

 on the outer side of each tooth, — and of the lower one narrower, 

 convex, with a single, subcentral, longitudinal, slightly impressed 

 groove. 



The fur of tliis Rat is moderately soft, like that of Mus rutins, the 

 longer hairs being rather rigid and bristle-like. 



The British Museum has lately received an adult and a young spe- 

 cimen of this Rat ill spirits from Cape York. The feet of the young 

 sjiecimen are as white, and, in proportion to the size of the specimen, 

 as thick and fleshy as those of the adult. 



The groove in the front of the lower cutting-teeth, the large size 

 and pale colouring of the feet, and the nakedness of the scaly tail 

 seem to indicate a peculiar section in the Rats, which may be called 

 Gymnomys. 



Ill the description above quoted I observed that there were two 

 other species of Rat in the British Museum, which had the tails 

 more or less \aried with yellow, and that one of them was from North 

 Australia, but that it differed from M. macropv.s in having smaller 

 feet. I might have added that it also differed from M. macropus 

 from Cape York in being a spiny-furred Rat. 



This Rat also belongs to the section Gymnomys. It diifers from 

 M. macropus in the small size of the cutting-teeth and the feet, and 

 there is also a difference in the colouring of the fur. It was brought 

 from Menado, North Celebes, by Mr. Wallace in 1859. 



This specimen might at first be regarded as the young of M. 

 macropus ; but the size and colour of the feet, as well as the great 

 difference in the fur, at once set at rest such a theory. The hair 

 of the Celebes Rat is much softer and uniform in kind than that 

 of the Rat from North Australia, which is much more rigid, with 

 abundance of elongate black cylindrical hairs ; and the shorter 

 fur is made up of soft slender crisp hairs, intermixed with a num- 

 ber of very narrow, slender, linear, rigid, white, flat, channelled 

 hairs. 



* P. Z. S. 1866, p. 221. 



t [See Mr. Krefft's paper, P. Z. S. 1867, p. 316. The same animal has been 

 more recently described and figui'ed by our Foreign Member Dr. \V. Peters imder 

 the name Vronuj^ macropus (Monatsb. Ac. Berlin, June 1867). — P. L. S.] 



