SCIURUS. 



131 



FIG. 20. SCIURUS IHESPEROSCIURUS) GRISEUS. 

 No. 6bo8 Field Columbian Mus. Coll. Nat. size 



Geogr. Distr. Oregon and northern California, into Lower Califor- 

 nia, Mexico. 



Genl. Char. . Size large; tail vertebrae as long as body and head; 

 upper premolars and molars, five; skull slender, elongate. 



Color. Above and outside of arms and legs grizzled bluish gray 

 and black; under parts pure white; tuft at base of ear chestnut; 

 tail above mixed gray, white, and black, with a white border, beneath 

 grizzled grayish white, with sometimes an ill-defined border and white 

 edge; hands grayish white to grizzled gray; feet gray to blackish gray. 



Measurements. Total length, 565; tail vertebras, 257; hind foot, 

 77; ear, 30^. Skull: average of five; basal length, 56.3; palatal 

 length, 32.1; interorbital width, 20.8; zygomatic width, 38.7; length 

 of upper molar series, 11.7. 



