New Guinea and neighbouring Islands. 263 
Stenomys * arrogans, sp. n. 
A medium-sized species, with a remarkably swollen brain- 
case. 
Head and body 120 mm.; tail 125; hind foot 25°5. 
Skull, length 34, breadth of brain-case 15°5. 
Hab. Doormanpad-bivak, 2400 m. (W. C. van Heurn). 
Type. Female. B.M. no. 22. 2. 2.24. Original num- 
ber 196. 
Melomys rattoides, sp. n. 
A large species, with close glossy fur and long slender 
skull. 
Head and body 210 mm.; tail 160; hind foot 41. Skull- 
length 48°5. 
Hab. Mamberano River (W. C. van Heurn). 
Type. Male. B.M. no. 22. 2.2.25. Original number 22. 
Melomys lanosus, sp. n. 
A soft-haired species, rather smaller than rattoides. Colour 
ereyish. 
Head and body 175 mm.; tail 143; hind foot 36°5. 
Skull-length 42. 
Hab. Doormanpad-bivak (W. C. van Heurn). 
Type. Female. B.M. no. 22. 2.2.27. Original num- 
ber 190. 
Melomys rubex, sp. n. 
Size small. General colour rufous. Under surface washed 
with pale rufous-grey, no hairs white to the base. 
Skull slender, smooth, not ridged. 
Head and body 132 mm. ; tail 130; hind foot 29. Skull- 
length 34:2. 
* A new genus related to Stenomys is :— 
NESOROMYS, gen. noy. 
Genotype: NV. ceramicus (Stenomys ceramicus, Thos, Ann. & Mag. Nat. 
Hist. (9) vi. p. 425, 1920). 
Distinguishable from Stenomys by long narrow muzzle; palate extended 
backwards nearly halfway from back of m* to front of bulla; palatal 
foramina far forward in front of molars; masseteric knob nearly halfway 
up the front edge of the zygomatic plate; and with unusually formed 
pterygoids. 
The peculiar characters of the Ceram representative of Stenomys were 
not sufficiently appreciated when I described the species, and I now 
think it should form a special genus. 
