SCIURUS. 113 



with black border and subapical bar and white edging; hands white 

 or whitish; feet grizzled gray. 



Measurements. Total length, 500; tail vertebrae, 247; hind foot, 

 70. Skull: average of five; basal length, 50.1; palatal length, 27.3; 

 interorbital width, 19.8; zygomatic width, 35.1; length of upper 

 molar series, 11.2. 



G. Echinosciurus. 



Premolars, |^|. Skull: broad, depressed between orbits; superior 

 outline curved, sharpest decline posteriorly; occipital region widest; 

 interorbital constriction very slight; rostrum broad and short; outer 

 side of nasals reaching ends of premaxillae; the nasals shorter than 

 width between orbits; basioccipital and basisphenoid broad, widely 

 separating audital bullae. 



FlG. 19. SCIURUS (ECHINOSCIURUS) AUREIGASTER. 

 No. 4744 Field Columbian Mus. Coll. Nat. size. 



