new Mainmah from South America. 267 



to do with either, in spite of its extreme rcsemblaace to them 

 externallj. 



Among some Muridai recently presented by Mr. L. Soder- 

 strom from Ecuador there are three specimens of a mouse 

 corresponding so closely with Tomes's description of his 

 ^'' Hesperomys minutus^^ that there can be no reasonable 

 doubt that they really represent tiiat animal. On comparing 

 tiiem with the skin from Pallatanga provisionally referre I by 

 me to minutus in 1894: *, the latter proves to be quite a 

 distinct species, which does not seem to liave been described, 

 and may tiierefore be called 



Oryzomys dry as, sp. n. 



A small Oryzomys of a deep rufous colour, but little lighter 

 below. Zygoma-root without anteriorly projecting plate. 



Size about as in 0. longicaudatus, rather larger than 

 0. minutus. Fur thick, close, and woolly, about 7-8 millim. 

 in length on the back. General colour above rich fulvous 

 rufous, lined with black on the back; sides clearer fulvous, 

 and this colour extends without line of demarcation all over 

 the under surface, where the hairs are slaty basally and 

 fulvous terminally. Ears of medium length, thinly clothed 

 with black hairs. Upper surface of hands and feet dull 

 whitish. Fifth hind toe reaching to the base of the second 

 phalanx of the fourth. Tail longer than head and body, very 

 finely scaled, thinly haired, brown above, rather paler below. 



Skull delicate, little ridged. Interorbital space narrow, 

 square- edged, but not ridged. Brain-case smooth, temporal 

 ridges scarcely perceptible. Interparietal broad transversely, 

 narrow antero-postcriorly. Zygomatic root very narrow, 

 without anterior projecting plate, the anterior edge vertical 

 and in the same line with the front edge of the bridge above. 

 Anterior palatine foi*amina rather large, parallel-sided, their 

 posterior extremity barely reaching to the front edge of m}. 

 Teeth small and delicate, apparently of the usual pattern, but 

 very much worn down in the type. 



Dimensions of the type (an old specimen of doubtful sex), 

 in skin : — 



Head and body 87 millim. ; tail (doubtfully perfect at 

 tip) 109 ; hind foot, without claws (moistened) 23 ; ear 

 (shrunk) 12. 



Skull : greatest length 24*5 ; basilar length 18 ; greatest 

 breadth 12'4; nasals 8*7 x 2'6 ; interorbital breadth 3-2; 



* Anu. & Mag. Nat. Hist. (6) xiv. p. So?. 



