SCIURUS. 121 
NELSON’s SQUIRREL. 
Type locality. Huitzilac, State of Morelos, Mexico. 
Geogr. Distr. Mountains south and west of the Valley of Mexico, 
and south of Valley of Toluca in the States of Mexico and Morelos. 
Genl. Char. Size large, colors dark. 
Color. Above blackish, grizzled with yellowish brown; top of 
head, ears, outside of arms and legs, hands and feet, black; sides of 
head grayish black, or yellowish brown; under parts blackish brown 
tinged with yellowish or rusty; tail all around at base like back, 
rest of upper part black washed with grayish white, beneath, yellow- 
ish gray and black with white edge; feet black. 
Measurements. Total length, 520; tail vertebra, 256; hind foot, 
70. Skull: average of five; basal length, 50.7; palatal length, 26.7; 
interorbital width, 19.4; zygomatic width, 34.9; length of upper 
molar series, I1.9. 
a.—hirtus (Sciurus), Nelson, Proc. Biol. Soc. Wash., x11, 1898, 
p- 153- 
MOUNTAIN SQUIRREL. 
Type locality. Tochimilco, State of Puebla, Mexico. 
Geogr. Distr. Mounts Popocatepetl and Iztaccihuatl, Mexico. 
Altitudes 8,o00—-12,000 feet, in States of Mexico, Puebla, and Morelos. 
Genl. Char. Similar to S. nelsont; gray area on back; tail broad, 
bushy. 
Color. Top of head and upper parts except middle of back, 
grayish brown; nose and middle of back bluish gray grizzled; ears, 
like crown, with white patch at the bases; chin and cheek gray; under 
parts ferrugineous; tail black above, washed with white, beneath 
grizzled rusty brown, bordered with black and edged with white; 
hands and feet gray. 
Measurements. Total length, 525; tail vertebrae, 260; hind foot, 
68. Skull: average of five; basal length, 50.2; palatal length, 26.5; 
interorbital width, 19.4; zygomatic width, 35.1; length of upper 
molar series, 11.8. 
83. collizi (Sciurus), Rich., Voy. Blossom, Zodél., 1839, p. 8. 
hypopyrrhus Alston, Proc. Zodl. Soc., 1878, p. 662. (Part.) 
CoLLige’s SQUIRREL. 
Type locality. San Blas, Territorio de Tepic, Mexico. 
Geogr. Distr. From northern border of Territorio de Tepic to Bay 
of Banderas, State of Jalicso, Mexico, below 2,500 feet. 
Genl. Char. Size large; pelage thin; tail long. 
Color. Above yellowish gray, tinged with black; nose iron gray, 
crown darker than back; outside of arms and legs dark gray; hands 
