122 Nelson A New Pigmy Squirrel 



Distribution. Known only from type locality. 



Specific cJiaracters. Pelage soft, thick and woolly; tail slender, flat 

 tened; upperparts olive brown; breast rusty rufous; rest of underparts 

 mainly grizzled bistre brown; tops of feet and toes washed with rusty. 

 Size about that of S. alfari. 



Color. Upperparts including sides of body and upper surface of legs 

 uniform olivaceous brown with a dull yellowish shade; sides of head 

 and neck slightly paler and more yellowish; tops of feet and toes washed 

 with rusty reddish; tail dull tawny olive finely washed and tipped with 

 black and thinly edged with pale yellowish tips of hairs; chin and throat 

 dingy rusty; underside of neck and breast rusty rufous shading back 

 into dull grizzled brown; underside of tail dull tawny olive narrowly 

 bordered with black and thinly edged with pale yellowish tips of hairs. 



Measurements. Measurements of type from dried skin: total length, 

 257; tail vertebrae, 116; hind foot, 37. 



Cranial characters. Premolars f . Skull longer and proportionately 

 narrower than in 8. istfimius; this character specially marked in rostrum; 

 interorbital width narrower; brain-case narrower and more highly arched, 

 lower jaw heavier with angle stronger and more broadly expanded; 

 molar series longer and heavier. The skull of type measures: palatal 

 length, 15.5; interorbital breadth, 14; length of upper molar series, 7. 



Specimens examined. One; from type locality. 



General notes. The soft thick pelage of this species indicates that it 

 is a resident of a comparatively cool and probably humid climate. 



The measurements of the apparently slightly over-stuffed type show 

 that it is about the same size as S. alfari. It may be at once distin 

 guished from S. isthmius, S. alfari, and 8. similis by the rather pale, al 

 most grayish, olivaceous color of upperparts, which entirely lack the 

 warm reddish brown suffusion characteristic, in varying degree, of the 

 three species named. 



