'MC) Mr. O. Tlioinas oji 



lliver, S. Australia, whicli, liavinp an incisive index of 70'^-71°, 

 I tliouglit must be new if" milchelli proved to be opistliodont ; 

 but, now that we know it to boorfliodont, they may be fairly 

 safely assigned to that species, beino- the oidy specimens 

 in this country with a recorded locality. In the British 

 ]\Iuseum we possess one specimen, without incisors, from 

 "New South Wides," collected by Mr. Stulchbury, and 

 another, of more d()ul)tful determination, from "Australia" 

 (Gould Collection). Whether the species is now completely 

 exterminated we do not know. 



The Alroy specimens would seem to demand description as 

 new : — 



Notomys alexis, sp. n. 



Size of i\". vn'tchelli. General colour sandy brown, paler 

 than in initchelli, but darker and browner than in cervinus. 

 Sides ])aler sandy. Under surface well-defined white, the 

 hairs with slat}- bases except on the throat and chest, where 

 they are white to the roots. Ears of medium length. Hands 

 and feet quite white. Tail fairly long, well pencilled for its 

 terminal third ; above sandy for its proximal half, then 

 blackish to the tip, below white throughout, the two colours 

 well contrasted terminally. 



Skull of fairly normal shape, not with enlarged brain-case 

 as in cervinus. Palatal foramina rather narrow and little 

 open. Mesopterygoid fossa narrow, scarcely broadened in 

 front, very diffeieiit from those of cervinus in this respect, 

 but agreeing with those of mitchelli. Bullae rather large. 



Incisors of all the specimens, old and young, markedly 

 opisthodont, their index commoidy about 51° to 56°. 



Dimensions of the type (measured in the flesh) : — 



Head and body 109 mm.; tail 135; hind foot 32; 

 ear 21. 



Skull : greatest length 30 ; cond3do-incisive length 28 ; 

 zygomatic breadth 17 ; nasals 10 ; interorbital breadth 5*2 ; 

 l)readili of brain-case 15 ; palatilar length 133 ; palatal 

 foramina 5Gxl*8; breadth of mesopterygoid fossa 1"7; 

 length of bulla G ; ujiper molar series 5*1. 



Hah. llegion of Alexandria, Nortiiern Territory of Aus- 

 tralia. Type from 35 miles S.W. of Alroy, about 135° 40' E. 

 and 19° 30' S. Alt. 800'. 



Type. Old female. B.M. no. 6. 3. 9. 35. Original num- 

 ber 151. (Collected 29th July, 1905, by W. Stalker. Pre- 

 sented by Sir VV. Ingram and the Hon. John Forest. Fifteen 

 specimens examined. 



