Ecuador and Venezuela. 455 



Skull : extreme length 36'2 ; basilar length 29*2 ; greatest 

 breadth 19"3 ; nasals 12-7 x 4*1; interorbital breadth 4"9 ; 

 brain-case, length 16"5, breadth just behind zygoma-root 16 ; 

 interparietal 5xl0"6; palate length from henselion 15*8; 

 diastema 10"2 ; palatal foramina 6'6x3; length of upper 

 molar series 6*2. 



Hal. Rio Milla, Merida, 1630 m. Coll. S. Briceno. 



Type : B. M. no. 98. 5. 15. 3. Killed March 7, 1897. 



This very peculiar species has a superficial resemblance to 

 0. meridensis, but may be readily distinguished externally 

 by its soft fur and dull-coloured belly. Its broad flat skull is 

 different from that of any species known to me, and even 

 recalls that of the South-African Graphiurus platyops. 



Marmosa marica^ sp. n. 



Most nearly allied to M. pusilluy Desm., but decidedly 

 larger. Fur rather long for this group, the hairs of the back 

 about 10 millira. in length. General colour greyish fawn, 

 not uniform, but decidedly wavy, the darker tips to the hairs 

 so disposed as to give a mottled or wavy appearance to the 

 back. Centre of face paler fawn. Area round eyes black. 

 Cheeks, chin^ and throat yellowish or creamy white, the hairs 

 light to their roots ; belly similar, but less strongly yellowish, 

 and the hairs slaty basally ; line of demarcation on sides not 

 strongly marked. Upper surface of hands and feet dull 

 whitish. Tail very short-haired, paler brown above, rather 

 whiter below. 



Skull much larger than in the typical M. pusilla. Muzzle 

 broad. Zygomata evenly and boldly expanded. Interorbital 

 space flat, parallel-sided, its edges just thickened into indis- 

 tinct parallel ridges, not forming postorbital processes. Palate 

 broad. Canines small. Last upper premolar slightly smaller 

 than the middle one. 



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



Head and body 102 millim. ; tail 131 ; hind foot (wet) 16'5 ; 

 ear 16. 



Skull : basal length 25 ; greatest breadth 15'6 ; nasals 

 12 X 3*6 ; interorbital breadth 4*8 ; palate, length 15, breadth 

 between outer corners of m.^ 8"5 ; combined length of ms.^'"^ 4*7. 



Hah. E.io Abbarregas, Merida, Venezuela, alt. 1630 m. 

 Coll. S. Briceno. 



Type : B. M. no. 98. 5. 15. 1. Killed Jan. 24, 1897. 



This is the species which, with some doubt, I referred to 

 M. pusilla in 1896, but the recent presentation to the Museum 

 of a Paraguayan specimen of that species, practically a topo- 



