SQUIRRELS OF MEXICO AND CENTRAL AMERICA 55 



probably representing a much worn phase of the summer pelage, has 

 very distinct well defined nape and rump patches of rusty brown ; top 

 of nose and back, including outside of legs and feet, pale iron gray 

 with very indistinct rusty rings on intermixed hairs ; chin and throat 

 white; underparts pale dull rusty washed with dingy white. 



Measurements. — Average of five adults from type locality : total 

 length 496. 8 ; tail vertebrae 249 ; hind foot 6S. 



Cranial characters. — Premolars \. Skulls average a little smaller 

 but are otherwise like those of S. poUopiis. Four adults skulls from 

 the type locality average : basal length 50.9; palatal length 26.9; in- 

 terorbital breadth 19.1; zygomatic breadth 34.5; length of upper 

 molar series 1 1 . 



Habits. — In December we found these squirrels feeding on acorns 

 of the large oaks among the pines on top of the Cordillera, but the 

 abundance of gnawed cones scattered on the ground showed that at other 

 seasons pines furnish their chief food supply. They were extraordi- 

 narily shy and cunning, and it was very difficult to secure specimens. 



Specimens examined. — Eight : all from the type locality. 



SCIURUS NELSONI Merriam. Nelson's Squirrel. 

 Sciiirus «^Zy£'«z Merriam, Proc. Biol. Soc. Washington, viir, p. 144, Dec. 1893. 



Type locality. — Huitzilac, Morelos, Mexico. Type no. 5 11 57 U. S. 

 National Museum, Biological Survey Collection. 



Distribution. — Oak and pine forests of Transition and Boreal zones 

 in mountains on south and west sides of Valley of Mexico, and south 

 side of Valley of Toluca, in the Federal District and States of Mexico 

 and Morelos (alt. Sooo-i 2,000 ft.). 



Characters. — Body large and heavy ; back grizzled, sooty blackish 

 brown ; feet black ; underparts grizzled blackish, sometimes washed 

 lightly with dingy yellowish brown or rusty rufous. Pelage veiy thick 

 and soft; under fur long; tail extremely broad and bushy. Teats: p. 



y a. 2 1. y. 



Color. — Upperparts sooty blackish usually washed or grizzled with 

 dull yellowish brown; head usually darker than back and sometimes 

 entirely black, shading gradually into color of back on nape ; ears, feet, 

 and sometimes outside of fore legs and lower thighs black ; sides of 

 head (when not black) grizzled blackish gray varying to dark yellow- 

 ish brown; lower cheeks and chin grayer; underparts grizzled and 

 varying from dingy blackish brown, thinly washed with dull yellowish, 

 to dark brown washed with dull rusty ; tail at base all around like 

 rump, rest of tail above black, washed with grayish white; below 



