Mammals from South America. 57,'i 



Distinguishable by the practically complete whiteness of 

 the belly-hairs. 



Philander laniger senex, subsp. n. 



Like Ph. 1. derbianus, with the following' exceptions : — 

 Head more entirely grey, the grey itself nearly white ; 

 mesial dark streak much less developed, almost imperceptible. 

 Light withers' mark more prominent, light grey. Under 

 .surface only whitish on small patches in chest and inguinal 

 regions, the rest, and inner sides of the limbs, washed with 

 pale tawny, like sides, but less glossy. Hind limbs like 

 sides, not greyish. Hairy part of tail hoary grey ; difference 

 between upper and lower extent of fur about 1^ inches. 



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



Head and body 257 mm. j tail 410; hind foot 14; 

 ear 33. 



Hah. Mindo, Ecuador. Alt. 4200'. 



Type. Adult female. 13.M. no. 13. 10. 24. 75. Original 

 number 150. Collected 25th June, 1913, by Gilbert Ham- 

 mond. Presented by Oldfield Thomas. 



This beautiful Philander is no doubt nearly allied to Ph. I. 

 derbianus, found in Colombia to the north of it, but may be 

 distinguished by its more prominently grey head and tawny- 

 washed under surface. 



Marmosa sobrina, sp. n. 



Related to M. fuscata of Merida, but with a pale line down 

 the centre of the underside. 



Essential characters, including the narrow unridged skull, 

 as in M. fuscata and incarta. General colour above of exactly 

 the same brown as M. fuscata, mummy-brown on the baelc 

 grading into a drabby brown on the sides ; quite without the 

 warm shade — approaching to rufous — of some of the 

 Peruvian species, such as impavida, Tschudi, and madescens, 

 Osgood. Face as in M. fuscata. Under surface, from chin 

 to anus, cream-buff along the centre, the pale area varying 

 from about a quarter of an inch wide on the belly to three- 

 quarters on the chest, the hairs pale to the roots; on each 

 side of the belly the hairs are slaty basally, greyish termin- 

 ally. Hands and feet dull whitish. Tail uniformly dark 

 brown to tip, the terminal half of the underside inconspicuously 

 lighter. 



fSkull very long and narrow, decidedly longer than in 

 fuscata and madescens. Nasals slightly expanded behind, 

 interorbital region smoothly rounded, without beading. 



Dimensions of the type (measured in flesh) : — 



Head and body 123 mm.; tail 150; hind Coot IS; 

 car 20*5. 



