SQUIRRELS OF MEXICO AND CENTRAL AMERICA 35 



Size medium, total length about 485 mm. ; me- 

 dian dorsal area rufous ; lateral line black 



durangi p. 85. 

 Back yellowish 



Ears pale rusty; flanks like back.../r«c/p. 61. 

 Ears dull rusty ; flanks washed with whitish 



sinaloensis p. 60. 



Back yellowish gray, coarsely grizzled with black 



Ears gray; yellowish of back dull, sometimes 



very indistinct collicei p. 58. 



Ears rusty; yellow of back brighter, more buffy. 



nuchalis p. 59. 

 Belly not blackish or white 

 Belly buffy 



Back with median area blackish or dark brown, rest of 



body buffy dorsalis p. 74. 



Back with median area not blackish 



Ears black edged variegatoides p. 79. 



Ears not black edged ftiaftaguensis i>. 81. 



Belly rufous 



Top of head paler than back 



AH of back blackish brown ; feet, legs, lower flanks 



and belly dull chestnut rufous adolphei ^. 73. 



Middle of back blackish or dark yellowish brown 

 or grayish yellow ; rest of body rufous 



dorsalis p. 74. 

 Top of head not paler than back 

 Back heavily washed with black 



Belly rusty I'ufous belti ^. 78. 



Belly rich dark ferruginous tkomast "p. 71. 



Back not washed with black 



Sack pale gray or sooty blackish 

 Back pale gray 



Feet dark gray or blackish ; rufous of belly 

 sometimes extending up on ribs 



aureogaster p. 38. 

 Feet pale gray ; rufous of belly not extending 



up on ribs chiapensis p. 69. 



Back sooty blackish, with thin wash of yellowish 



gray 



Back uniform nelsoni p. '^$. 



Back with area of bluish gray across the mid- 

 dle hirtus p. 56. 



Back not pale gray or sooty blackish 



Back yellowish brown sometimes thinly washed 



with gray .griseojlavus 1^. 67. 



Back blackish, grizzled with gray or yellowish ; 

 underparts and costal area rufous 



hypopyrrhus p. 42. 



