126 SCIURUS. 



Measurements. Total length, 460; tail vertebrae, 230; hind foot, 

 55. Skull: basal length, 45; palatal length, 23; interorbital width, 

 16.2; zygomatic width, 19; length of upper molar series, 9.5. 



a. baliolus (Sciurus), Nelson, Proc. Biol. Soc. Wash., xiv, 1901, 



p. 131. 

 SWARTHY SQUIRREL. 



Type locality. Apazote, State of Campeche, Mexico. 



Geogr. Distr. Southern part of State of Campeche, and eastern 

 part of State of Tabasco, Mexico. 



Genl. Char. Similar to S. yucatanensis , but darker. 



Color. Above blackish gray suffused with buff; beneath iron 

 gray; legs and hands grizzled with buff or gray; feet black; tail black, 

 washed with gray. 



Measurements. Total length, 464; tail vertebras, 238; hind foot, 

 59- 



89. thomasi (Sciurus), Nelson, Proc. Wash. Acad. Scien., i, 1899, 



p. 71. 



booikicB (nee Gray), Allen, Mon. N. Am. Rodent., 1877, pp. 741- 

 746. (Part. Costa Rica.) 



hypopyrrhus Alston, Proc. Zool. Soc., 1878, pp. 662-664. (Part. 



Costa Rica specimens.) 

 THOMAS' SQUIRREL. 



Type locality. Talamanca, Costa Rica. 



Geogr. Distr. "Humid tropical forests of eastern Costa Rica." 



Genl. Char. Hair on back coarse, stiff, glossy; tail long, narrow. 



Color. Crown and upper parts of body, sides of neck, outer side 

 of arms and legs, and base of tail black, the yellowish under color 

 appearing; chin and sides of head grayish brown; under parts ferru- 

 gineous, irregularly varied with white; tail above black, washed with 

 white, beneath grizzled black and yellowish brown, bordered with 

 black and edged with white ; feet black or grizzled f errugineous ; ears 

 blackish, with basal f errugineous patch, and black tufts. 



Measurements. Average total length, 517.5; tail, 246.5; hind foot, 

 62.2. Sku}l: basal length, 50; palatal length, 26.2; interorbital width, 

 22; zygomatic width, 35.5; length of upper molar series, 11.5. 



90. adolphei (Macroxus), Less., Nouv. Tabl. Regn. Anim. Mamm., 



1842, p. 112. 

 boothicB Allen, Mon. N. Am. Rodent., 1877, p. 741. (Part. 



Nicaragua.) 

 hypopyrrhus Alston, Biol. Centr. Amer. Mamm., i, 1880, p. 128. 



(Part.) 



