338 THOMOMYS. 



Color. Upper parts dark umber brown; sides fulvous; under 

 parts buffy fulvous; under side of face blackish; feet and apical 

 third of tail white. Melanistic phase, which the type represents, is 

 slate black all over, except ends of fore and hind feet and the apical 

 third of tail and inside of cheek pouches, which" are white. 



Measurements. Total length, 217 ; tail vertebrae, 68; hind foot, 30. 



340. atrovarius (Thomomys), Allen, Bulh Amer. Mus. Nat. Hist., 



1898, p. 148. 

 TATAMELES POCKET GOPHER. 



Type locality. Tatameles, State of Sinaloa, Mexico. 



Geogr. Distr. State of Sinaloa, Mexico. Range unknown. 



Genl. Char. Size medium; nasals narrow; similar in color to 

 T. orizabce. 



Color. General hue plumbeous, tinged with brown above and 

 with gray on the under parts, the tips of the hairs being of that color; 

 tail hairs plumbeous and gray. 



Measurements. Total length, 210; tail vertebrae, 65; hind foot, 

 28; ear, 7. Skull: total length, 40; zygomatic width, 24.5; mastoid 

 width, 19.5 ; interorbital width, 7 ; length of nasals, 9 ; width of nasals 

 anteriorly, 3.7. 



341. toltecus (Thomomys), Allen, Bull. Amer. Mus. Nat. Hist., 



1893, p. 52, pi. i, fig. 13. 

 JUAREZ POCKET GOPHER. 



Type locality. Juarez, northern part of State of Chihuahua, 

 Mexico. 



Geogr. Distr. State of Chihuahua, Mexico. Extent of range 

 unknown. 



Genl. Char. Larger than T. fulvus. Skull heavy, broad ; pre- 

 maxillae much longer posteriorly than nasals ; interparietal very small ; 

 upper incisors slightly grooved. 



Color. Upper parts grayish rufescent brown, lined with black 

 on median line; under parts pale grayish buff; tail and feet grayish 

 buff; edge of cheek pouches white. 



Measurements. Total length, 230; tail vertebras, 60; hind foot, 

 27. Skull: total length, 43; basilar length, 40; greatest zygomatic 

 breadth, 27 ; interorbital constriction, 7 ; length of nasals, 14. 



342. perditus (Thomomys), Merr., Proc. Biol. Soc. Wash., xiv, 1901, 



p. 108. 

 LOST POCKET GOPHER. 



Type locality. Lampazos, State of Nuevo Leon, Mexico. 

 Geogr. Distr. Range unknown. 



