9<> SCIURUS. 



b 5 . Back dark gray; top of head PAGE 



iron gray or blackish S.a. hypopyrrhus 116 



b. 4 Ribs and shoulders not rufous. 

 a. 5 Back dingy whitish; nape patch 



rusty S. socialis 1 23 



b. 5 Back bluish gray in middle, re- 

 mainder sooty brownish S. n. hirtus 121 



b/" Feet white. 



a. 4 Back whitish, rump and nape 



patches very bright S. s. cocos 1 24 



b. 4 Back gray. 



a. 5 Nape patch strongly marked, 



dark rufous 5. p. effugius 1 20 



b. 5 Nape patch not strongly marked, 



rusty yellowish 5. poliopus 117 



b/ Nape and rump patches absent or not 



well defined. 



a." Nape and lump patches not well defined, 

 a/" Back dark gray, sparingly or not at 



all mixed with yellowish hairs. 

 a. 4 Back and under side of tail dark 



iron gray; feet gray 5. p. cervicalis 119 



b. 4 Back and under side of tail paler 



gray; feet white S. p. nemoralis 118 



b/" Back pale gray mixed with yellowish 

 hairs; feet white. 



a. 4 Belly white 5. p. Hernandez'. 118 



b. 4 Belly rufous S. poliopus 117 



b/' Nape and rump patches absent. 



a/" Back with broad median band of 



blackish; rest of body whitish S.a. dor salts 127 



b/" Back without broad median band 



of blackish. 

 a. 4 Belly pale gray; back coarsely griz- 



. zled gray or yellowish gray S. yucatatiensis 125 



b. 4 Belly dark iron gray ; back blackish 



gray suffused with buff S. y. baliolus 126 



c. 4 Belly bright ferrugineous; back yel- 

 low ferrugineous or blackish brown . . 5. v. mornlus 105 

 d. 4 Belly blackish or white. 

 e. 5 Belly blackish. 



a. 6 Back sooty blackish grizzled 



with yellowish gray S. nelsoni 1 20 



