from the Neotropical Region. 305 



face. Interorbital region flat, its edges square, not heavily 

 ridged. Palatal foramina rather narrow for the group, ex- 

 tending backward to the level of the front of "^li. Bullre 

 rather, though not measurably, larger than in the allied 

 species of the group. 



Dimensions of the type (an adult female in skin) : — 



Head and body 113 millim.; tail 125, with terminal tuft 

 141 ; hind foot (moistened) 24; ear (dry) 14. 



Skull : basal length 25-7 ; basilar length from henselion 

 23*8; greatest breadth 16*6; nasals 10*5 x 3*7; interorbital 

 breadth 4-3, interparietal 4-1 x 10-6; palate length from 

 henselion 12-8; diastema 8; palatine foramina 6"2x2-2; 

 length of upper molar series 4-7. Lower jaw : condyle to 

 incisor-tip 18*8. 



Hah. Agua Dulce, W. Cundinaraarca, Colombia. 



Type collected Sept. 19, 1895. 



This pretty Vesper-rat differs from all other members of 

 Rhipidomys by its slate-mixed fulvous belly, this part being 

 in the other species perfectly pure white. A very young 

 specimen from Fauabistd, corresponds in all respects with the 

 old one. 



Oryzomys niveipes, sp. n. 



General appearance remarkably like 0. lantger, Thos., 

 although it is slightly larger. Fur very long, soft, and 

 fluffy. General colour dull olive-fulvous, darker mesially 

 above, clearer and paler along the sides and below ; line of 

 demarcation on sides indistinct. Hairs everywhere above and 

 below slate-coloured basally. Ears large, well-haired, black. 

 Hands and feet silvery white above, without darker meta- 

 tarsals. Tail long, thinly haired, brown above, paler below. 



Skull very different from that of 0. laniger. Face long 

 and slender, with a narrow muzzle and long, narrow, parallel- 

 sided interorbital region, whose edges are rounded and not 

 ridged. Brain-case smoothly rounded, not broad in propor- 

 tion to its length. Zygomatic plate little projected forward. 

 Palatal foramina reaching just past the anterior end of—. 



Dimensions of the type (an adult male in skin) : — 



Head and body 113 millim.; tail 140; hind foot 26; 

 ear 18. 



Skull : basal length 2G'8 ; basilar length from henselion 

 25; greatest breadth 16; nasals 12*4 x 3*8; interorbital 

 breadtii 4, interparietal 3*5xl0'5; palate length from hen- 

 selion 13*2; diastema 8'7; palatal foramina 7x2*4; length 

 of upper molar series 5. Lower jaw : condyle to incisor- 

 tip 19-5. 



