114 SCIURUS. 
KEY TO THE SPECIES AND SUBSPECIES OF THE SUBGENUS, 
A. Size large. Premolars, — 
a. Above iron gray. iy PAGE 
a.’ Nape yellowish brown or rusty rufous...S. auretgaster 115 
b.’ Nape grizzled rufous or brownish....S. a. hypopyrrhus 116 
c.’ Nape yellowish or rufous brown....... S. a. frumentor 117 
d.’ Nape grizzled yellowish brown to chestnut 
OW eats ue seats Reker en heres ogee eee S.p.nemoralis 118 
e.’ Nape yellowish brown to rusty tinged 
withsblack:.7 on descends ee meee eres S. p. colimensis 119 
f.’ Nape rusty rufous, sometimes mixed 
with black: andievinite ss tps oe ee ....5. p. effugws 120 
g.’ Nape fulvous or rusty brown, grizzled 
WLC Es MOL LC Kye. Siete so erent tee are ene vee aetna S. p. cervicalis 119 
b. Above gray mixed with brown or yellow...... S. polopus 117 
c. Above pale gray and yellowish.......... S. p. hernandezi 118 
d. Above blackish, grizzled with yellowish brown. ..S. nelsoni 120 
e, Above bluish eray;orizzledern 5. se eee S.n.hirtus 121 
f. Above yellowish gray tinged with black. 
a.’ ars yellowish: DrO Wilts. «* = s/c eee S. collet -E2x 
bl Bars rusty TutOus 2.x. sRos ic 2 ne S.c. nuchalts 122 
g. Above pale reddish, yellow, and black...... S. sinaloensis 122 
he Above ervzzled dark yellowish. 5... 0. -1.. niae een S. iui 123 
i. Above mixed white and black, tinged with 
yellowish Or TutOUus.. :c0 05 fees ono eee S.. SOGLGIS pres 
j; Above grayishyor creamy whiter en . 25) S. S$€0605 G24 
k. Above grizzled yellowish brown, washed 
WithicwHite slau: SS ene cn Oe ee oeeee S. grisetflavis 124 
le SAbowe! omzzledteraya:. wy cere eee ae S. g. chiapensis 125 
m. Above grizzled gray and black, tinged with 
yellowish: brOwils eee erie ors ree S. yucatanensis 125 
n. Above blackish gray, suffused with buff ...S. y. baltolus 126 
6: Abovesblack 5... 74 ake oor ee eee S. thomasi 126 
p. Above dark brown, mixed with grayish....... S. adolphet 126 
q. Above dorsal band blackish or grayish 
yellowish» browne. 55.415 Sen ke oe ea S.a.dorsalis 127 
r, Above dark chocolate: «2 <iten.... e eee S.melamia 128 
s. Above grizzled grayish brown. 
a. Winged. with teddish su, {7 aa. a. 22 ee ee S. boothie 128 
b.! Washed with black\.2)..... skies. te ae ee S. 6. beltt 128 
t. Above grizzled yellowish gray............ S. vartegatoides 129 
u. Above grizzled yellowish brown, dorsal re- 
Clon washedwwith, blacks. pt ae eee S. managuensis 129 
