Mammals from Kimherley, Australia. 151 



zygomatic breadth 8'6 ; mastoid breadth 7"4 ; palato-sinual 

 length 4*6 ; front of canine to back of m^ 4*5. 



Type as above. 



This well-marked little species, which I have named after 

 its discoverer, may be readily distinguished from its only near 

 ally Ch. nigrogristus by its hoary colour and the smaller size 

 of its skull. 



2. AIus ferculinus, Thos. 



S . 2. Parry's Creek. 



1 fail to find any satisfactory means of distinction between 

 this and the type from Barrow Island, N.W. Australia. 



3. Mesemhriomys'^ arguras I'ndutus, subsp. n. 



(J. 1,6, 8; ? . 4. Parry's Creek ; near sea-level. 



tSimilar to typical argurus m all respects, except that the 

 tail, instead of being wholly white above and below, is 

 distinctly and sharply bicolor, dark brown along the upper 

 surface, white on the sides and below ; it is also rather more 

 heavily pencilled. 



Dimensions of the type (measured in flesh) : — 



Head and body 107 mm. ; tail 96 (not quite perfect, another 

 specimen 109) ; hind foot 22 ; ear 18. 



Skull : greatest length 33'5 ; basilar length 25"7 ; nasals 

 11'6; interorbital breadth 4"8 ; palatilar length 15; dia- 

 stema 8*6 ; palatal foramina 6"6 ; upper molar series 5*5. 



Type. Adult male. Original number 1. Collected 13th 

 Aug., 1908. 



These specimens are the first we have had in skin of this 

 form of Mesemhriomys, the type and only known example of 

 M. argurus being in spirit. That type was purchased from 

 a collector who traversed Australia from north to south, and 

 it is probable that it was obtained in the interior desert-region, 

 which would account for its whitened tail as compared with 

 the brown tail of this northern coast subspecies. 



Mr. Piogers states that this animal has a thickened fatty 

 tail, as also has AJ. pedunculatus, this character being rarely 

 found among Muridie, although in other groups it often 

 occurs in the inhabitants of desert regions. 



* Ammomys, Thos. Ann. & Mag. Nat. Hist, (7) xvii. p. 84 (1906) rnec 

 Raf.). f y ^ . 



