new Species o/Oxymycfcrus and Tliricliomys. 227 



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



Head and body 140 milUm. ; tail 100 ; hind foot, s. u. 30, 

 c. n. 34; ear 22. 



Skull: greatest length 395; basilar length 29'7 ; zygo- 

 matic breadth 16'2 ; nasals, length 16'5, breadth anteriorly 

 4*4; interorbital breadth 61; brain-case breadth 14*5; 

 palatal length 15 ; palatal foramina 8"4 ; diastema 9'5 ; 

 breadth of palatal bridge 4-8 ; length of upper molar series 5*8. 



Ilah. Serra do Mar, S.E. Brazil. Type from Ro9a Nova, 

 Parana, altitude 1000 m. ; other specimens from Santa 

 Cathcrina {Ilicring) and Theresopolis, Rio Janeiro [Gjeldi]. 



Type. Female. Original number 892. Collected 2nd 

 November, 1901, by Mr. Alphonse Eobert. 



Tills species, coloured quite like O. nasutus, Waterh., 

 differs from that by its larger size, from O. hispidus, Pict,, 

 of Bahia, by its smaller size and narrower brain-case, and 

 from 0. rosfellatus, Wagn., from " Brazil," by various cranial 

 details, of wliich the most tangible is its more elongate palate, 

 that species having its posterior nures level with the back of 

 the second molar. 



Thrlchomys Fosteri, sp. n. 



Closely allied to the only known species of the genus, 

 7\ opereoi'des, from Lagoa Santa, but darker in colour, with 

 blacker tail, broader palatal foramina, and larger bullse. 



Size as in T, apereoides, or slightly larger. General colour 

 of whole upper surface grizzled *' broccoli-brown," the hairs 

 light slate basally, darkening distally towards the drab sub- 

 terminal ring, their extreme tips black. Sides paler and more 

 drab. Under surface sharply defined white, the hairs pale 

 slaty at their bases, except in the inguinal region, where they 

 are wholly white; a band across the chest greyish brown. 

 Head like back above, a small, sharply defined, elongate 

 ^vhite patch above eye, another below it, and a third at the 

 outer base of the ear. Lips and chin white. Ears practically 

 }iaked, their few fluffy hairs greyish. Outer sides of arms 

 and legs like body, or rather more cinereous ; inner sides 

 white; centre of metapodials brown, edges, and fingers and 

 toes, white. Tail furred and coloured like the body for its 

 basal inch, then above it is completely black across its whole 

 breadth to the tip ; below the proximal half is greyish, 

 gradually darkening to black distally. In T. apereoides the 

 black forms a comparatively narrow line above, and the 

 light of the lower surface extends further towards the tip. 



Skull very similar to that of T. apereoidesy but rather 



