428 Mr. O. Thomas— Notes 



colour more sti-ongly ocLraceous than in the allied specie!?; an 

 indistinct ochraceous-buff line edo-iug the up})er colour, this 

 line particularly noticeable along the cheeks and sides of the 

 neck. Under surface dull buffy whitish, the hairs mostly 

 whitish to their bases. Ears almost naked, their fine hairs 

 white. Hands and feet white. Tail very thinly haired, 

 brown above, slightly lighter below. Mamm^ normally 

 2 — 3 = 10 as usual, but on one side of one female there 

 appears to be an additional, pectoral mamma. 



Skull like that of R. iiinneyi, but considerably larger, more 

 strongly built, and more heavily ridged. Palatal foramina 

 surpassing the tirst third of «i\ Bailee very large. 



Dimensions of the type (measured in flesh) : — 



Head and body 173 mm.; tail 135; hind foot 30; 

 ear 19. 



Skull: greatest length 40; condylo-incisive length 39*4; 

 zvi2,omatic breadth 21'8; nasals 15 x 5'2 ; interorbital breadth 

 5*8 ; breadth across parietal ridges 15 ; palatal foramina 9*2; 

 bulla 10"2 ; upper molar series 7"5. 



Ilah. Melville Island, off the Northern Territory of South 

 Australia ; type from Biro, Apsley Strait. 



Type. Adult male. B.M. no. 13. 6. 28. 33. Original num- 

 ber 14. Collected 27th November, 1911, by Mr. J. P. 

 Rogers. Three specimens, of which one is not fully adult. 



Readily distinguishable from all other members of the 

 group by its large skull and large bulla?. 



Rattus mondraineus, sp. n. 



Nearly allied to R. fuscipes of Western Australia, with 

 which it shares the getieral size, long loose fur, and brown 

 colour. But, externally, the colour is greyer, the buffy sub- 

 terminal rings on the hairs (which give the brown tone to 

 fuscipes) being less developed, so that the blue-grey of the 

 uiidertur is more perceptible. Under surface lighter, tiie 

 ends of the hairs more whitish. Throat noticeably more 

 whitish than rest of under surface. Hands and feet whitish 

 above, without tinge of brown. Tail as in fuscipes^ mode- 

 rately haired, brown above and below. 



Skull with the nasals of normal proportions, not so 

 unusually narrowed behind as they are in fuscipes. Inter- 

 orbital region broader, its edges squarish, not sharply angular, 

 and not ridged. Palatal foramina of medium length, rather 

 narrow. Builai rather small. Molars decidedly smaller than 

 in fuscipes. 



Dimensions of the type (taken on the skin) : — 



Head and body IGO mm.; tail 138; hind foot 30. 



