SCIURUS. 123 
with basal brownish yellow patches; under parts white; tail above 
grizzled brownish yellow, washed with white, beneath similar in 
color, bordered with black and edged with white. 
Measurements. Total length, 524; tail vertebra, 255; hind foot, 
62. Skull: basal length, 53; palatal length, 26.3; interorbital width, 
20; zygomatic width, 34; length of upper molar series, 11. 
85. truii (Sciuwrus), Nelson, Proc. Wash. Acad. Scien., 1, 1899, p. 61. 
TRUE’S SQUIRREL. 
Type locality. Camoa, Rio Mayo, State of Sonora, Mexico. 
Geogr. Distr. Southwestern part of the State of Sonora and 
northern portion of the State of Sinaloa, Mexico. 
Genl. Char. Similar to S. coliei, but back dark yellowish and 
skull differently proportioned. 
Color. Upper parts grizzled dark yellowish; sides of head yellowish 
gray; ears rusty; basal patches same color; outside of arms, legs, 
hands and feet dark gray; under parts white; tail like back at base, 
remainder above mixed black and dark yellowish tinged with white; 
beneath similar, with an ill-defined black border and white edge. 
Measurements Total length, 485; tail vertebre, 254; hind foot, 
66. Skull: average of four; basal length, 47.7; palatal length, 24.3; 
interorbital width, 18.3; zygomatic width, 33.2; length of upper 
molar series, II. 
86. socialis (Sciurus), Wagn., Abh. Math. Phys. Cl. K. Bayer. Akad. 
Wiss., Munchen, 11, 1837, pp. 501-7, pl. v. 
aureigaster Allen, Mon. N. Am. Roden., 1877, p. 750. (Part.) 
leucops Allen, Mon. N. Am. Roden., 1877, p. 753. (Part.) 
variegatus Alston, Proc. Zodl. Soc., 1878, p. 660. (Part.) 
TEHUANTEPEC SQUIRREL. 
Type locality. Near Tehauntepec City, State of Oaxaca, Mexico. 
Geogr. Distr. Puerto Angel, State of Oaxaca, south to Tonala 
and Tuxtla, State of Chiapas, Mexico, below 3,000 feet. 
Genl. Char. Color variable; *nape patch, when present, rusty 
rufous; under parts from white to ferrugineous. 
Color. Above mixed white and black tinged with yellowish or 
rufous; nape blackish rusty rufous; rump patch sometimes exhibiting 
rusty rufous; cheeks, space around eyes, and bases of ears yellowish 
brown; orbital ring dull fulvous; under parts white; tail like rump 
all around the base, remainder above black washed with white, 
beneath from fulvous gray to orange, bordered by black and edged 
with white; hands and feet like back. 
* Specimens from near Tonala are usually without nape patch. 
