108 SCIURUS. 
Genl. Char. Similar to S. oculatus, but paler. Skull: nasals 
narrow. 
Color. Top of head and back gray, washed with blackish; flanks 
and outside of arms and legs grizzled gray, tinged with yellowish; 
orbital ring grayish white; sides of head and ears gray, tinged with 
buff; white basal patches on ears; under parts whitish; hands and 
feet grayish white, tinged with buff; tail black above, washed with 
white, beneath yellowish gray or brown, bordered with black and 
edged with white. 
Measurements. Total length, 520; tail vertebre, 260; hind foot, 
66. Skull: average of two; basilar length, 54; palatal length, 29; 
interorbital width, 20.5; zygomatic width, 36.7; length of upper molar 
series, II. 
75. alleni (Sczurus), Nelson, Proc. Biol. Soc. Wash., x11, 1898, 
p. 147. 
carolinensis? Baird, N. Am. Mamm., 1857, p. 263. 
carolinensts Allen, Mon. N. Am. Roden., 1877, p. 706. 
carolinensis Alston, Proc. Zodl. Soc., 1878, p. 658. 
arizonensis Allen, Bull. Am. Mus. Nat. Hist., N. Y., 1891, p. 222. 
(Bares) 
ALLEN’S SQUIRREL. 
Type locality. Monterey, State of Nuevo Leon, Mexico. 
Geogr. Distr. From Monterey, State of Nuevo Leon, into State of 
Tamaulipas, Mexico. Altitude, 2,000-8,500 feet. 
Genl. Char. Similar to S. carolinensis, back uniform in color. 
Color. Above grizzled yellowish brown, grayest on flanks; arms, 
hands, and feet whitish gray; thighs like flanks; orbital ring whitish; 
under parts white; faint grayish lateral line; tail like back all around 
the base, above black washed with white, beneath grizzled yellowish 
gray, bordered with black and edged with white; ears brownish gray. 
Measurements. Total length, 471; tail vertebre, 217; hind foot, 
60. Skull: average of five; basilar length, 50.4; palatal length, 26.3; 
interorbital width, 18.4; zygomatic width, 33.7; length of upper 
molar series, 10.3. 
76. nayaritensis (Sciurus), Allen, Bull. Am. Mus. Nat. Hist., N. Y., 
1890, p. vil, footnote, and p. 185. 
alstoni Allen, Bull. Am. Mus. Nat. Hist., N. Y., 1889, p. 167. (nec 
Anderson.) 
NAYARIT SQUIRREL. 
Type locality. Sierra de Valparaiso, State of Zacatecas, Mexico. 
Geogr. Distr. States of Jalisco and Zacatecas, Mexico. 
Genl. Char. Similar to S. grisetflavus; ears high and broad. 
