Rodents from Western South America. 299 



uniform reddish on the sides. Ears well haired, blackish 

 brown. Chin prominently contrasted white ; whole re- 

 mainder of under surface rich ochraceous rufous, not defined 

 laterally from the red of the sides ; bases of the hairs indis- 

 tinctly plumbeous. Upper surface of hands and feet blackish 

 brown. Tail well haired throughout, blackish brown, slightly 

 lighter along the median line below. 



Skull long, the muzzle of the peculiar trumpet- shape 

 characteristic of the large Brazilian species of the 0. hispidus 

 group. Nasals long, broadest anteriorly, reaching backwards 

 to the level of the front edge of the anteorbital bridge ; supra- 

 orbital edges as usual, not beaded or ridged, but there is a 

 slight angular projection in the position of the postorbital 

 processes, whence parietal ridges run nearly directly backwards, 

 giving the brain-case an oblong parallel-sided appearance ; 

 interparietal well developed j anterior zygoma-root much 

 slanted backwards ; palatal foramina large, widely open, 

 extending backward to the middle of m.\ 



Dimensions of the type (measured in flesh by the col- 

 lector) : — 



Head and body 135 millim. ; tail 105 ; hind foot, s. u. 

 30, c. u. 33; ear 21. 



Skull : greatest length 38 ; basilar length 30 ; zygomatic 

 breadth 18; nasals 143 X 5; interorbital breadth 6'7 ; tip 

 to tip of rudimentary postorbital processes 11*7 ; interparietal 

 2-6x6; diastema 9; palatal foramina 8 X 3*2 j length of 

 upper molar series 5" 7. 



Hah. Perene, Ucayali watershed, Department of Junin, 

 E. Peru. Altitude 800 m. 



Type. Male. B.M. no. 0. 7. 7. 45. Original number 

 925. Collected 10th April, 1900, by Mr. P. O. Simons. Four 

 specimens examined. 



This is the first Peruvian Oxymycterus described. Its 

 size and cranial characters will readily distinguish it from 

 any known species. 



In the same collection, Mr. Simons secured at Galera, the 

 highest point of the Oroya railway, altitude 4800 m., an 

 example of the remarkable Neotomys ebriosus, Thos., described 

 in 1894* trom a specimen collected by Mr. J. Kalinowski in 

 the Valley of Vitoc. Mr. Simons's skin shows that the under- 

 side of the tail is not white but dull buffy, and that the 

 chest is dirty brownish, a colour which runs backward a short 

 distance along the centre of the belly. 



* Ann. & Mag. Nat. Hist. (6) xiv. p. 348. 



20* 



