766 MR. OLDFIELD THOMAS ON [Nov 13, 



colour above pale Iiair-brown with a tinge of buffy, the lining 

 from the dark tips of the longer hairs well-marked. Individually 

 the ordinary hairs are dark slaty for three-fourths their length, 

 their ends dull clay-colour. Under surface similar to upper, but 

 rather paler, without lines of demai-cation. Ears of medium 

 length, their proectote black, their metentote grizzled blackish, 

 their edges with a well-defined white rim. Upper surface of 

 hands and feet dull greyish white. Tail leather short, well- 

 haii-ed, the scales quite hidden ; dark brown above, dull white 

 below. 



Skull with many of the essential characters of that of M. lineo- 

 latus, but smaller, the supraorbital margins more sharply angular, 

 the front edge of the zygomatic plate less deeply concave, the 

 palatal foramen much shorter, and the bullfe smaller. The 

 palatal foramina ai-e narrowly pointed behind, and barely pi'oject 

 between the front of the roots of m\ Mesopterygoid fossa 

 broadly open, the palatal edge well in front of the anterior end 

 of the parapterygoid fosspe. 



Molars constructed as in If. Uneolaius, but narrower, though 

 broadei- than in M. higginsi. 



Dimensions of the type, measured in the flesh : — 



Head and body 145 mm. ; tail 110 ; hind foot 27 ; ear 20. 



Skull — greatest length 32 mm. ; basilar length 26 ; greatest 

 breadth 17-2 ; nasals 11-5 X 37; interorbital breadth 4-2 ; breadth 

 of brain-case 14-4 ; palatilar length 14-6 ; palatal foramina 7x2; 

 length of upper molar series 5-7 ; breadth of m' 2. 



Hab. & t'i/2)e as above. 



This Eat, which I have much pleasure in naming after its 

 captor, belongs to the peculiar Australian group of which Mus 

 lineolatus Gould, of New South Wales, and M. higginsi Trouessart 

 {M. leucojms Higg. & Pett.), of Tasmania, have hitherto been the 

 only known members. Within the group the Tasmanian species 

 is at once distinguished from both the Australian forms by its 

 very long tail and narrow molars, while the new western species 

 may be separated from its eastern ally by its rather smallei- size, 

 paler colour, and by the cranial characters above noted, of which 

 the most tangible are the narrowness of the molars and the 

 shorter palatal foramina. 



16. Mus ALBOCINEUEUS Gould. 



22 from Stockpool and Dwaladine. 



" Frequenting sand plains ; plentiful east of Beverley. Their 

 bui-rows differ fi'om those of Notomys gouldi by having sand 

 thrown up ai-ound them ; they also often seem to fill up the 

 entrance of these burrows when inside — when they are very 

 difficult to detect." ^(?. C. S. 



17. Mus MUSCULUS L. 



5 from various localities. 



" The common House-Mouse, besides swarming in all the 



