SCIURUS. 103 
Measurements. Total length, 384; tail vertebrze, 189; hind foot, 
54. Skull: average of four; basal length, 41.7; palatal length, 21.4; 
interorbital width, 15.3; zygomatic width, 28.4; length of upper 
molar series, 9.1. 
C. Guerlinguetus. 
Size small; ears long; tail shorter than body, flat, bushy. Skull 
broad, braincase not highly arched, expanded at parietal region; 
bulle small; rostrum broad, deep; nasals long, widest anteriorly; 
I I 
post-palatal notch behind last molar. Premolars, ; 
: 
Fic. 15. SciurRus (GUERLINGUETUS) 4. HOFFMANNI. 
No. 4749 Field Columbian Mus. Coll. Nat. size 
KEY, FTO THE SPECIES AND SUBSPEGIES OF THE SUBGENUS. 
A. Size small; tail flat, bushy. PAGE 
a. Upper parts grizzled rusty brown...... .S. @. hoffmannt 104 
b. Upper parts blackish brown and tawny. .S. @. chiriquensis 104 
c. Upper parts dark ochraceous brown.........S. richmondt 105 
