78 



U.S. NATIONAL MUSEUM BULLETIN 2 75 



c _ 



14 | ^ I ? 



Figure 9. — Statistical comparison of least interorbital breadth of the species of Gerbillus. 

 Notation remains the same as in figure 5. 



B _ 



C _ 



_ 20 



o" 



o 



6 



Figure 10. — Statistical comparison of upper molariform toothrow of the species of the 

 subgenus Gerbillus: A, G. aureus; B, G. eatoni; C, G. gerbillus; D, G. pyramidum. 



