336 THOMOMYS. 



Gcogr. Distr. Lower California, Mexico, north into southern 

 California. 



Genl. Char. Size large; claws short, thick; Skull massive, 

 angular; dentition weak; interparietal longer than wide. 



Color. Above tawny brown; rump lighter; head blackish; ears 

 and aural patch sooty; beneath tawny ash; feet and lower surface 

 of limbs ash. 



Measurements. Total length, 260; tail vertebrae, 89; hind foot, 

 33.5. Skull: total length, 39; zygomatic brea-dth, 24.4; basilar 

 length, 35.5; nasals, 11.9; interorbital constriction, 6.9; length of 

 mandible, 25. 



(I. intemnedius (Thomomys), Mearns, Proc. U. S. Nat. Mus., 1897, 



xix, p. 719. Elliot, Syn. N. Am. Mamm., 1901, p. 228. 

 PLATEAU POCKET GOPHER. 



Type locality. Huachuca Mountains, southern Arizona. Alti- 

 tude, 9,000 feet. 



Geogr. Distr. Mountains connecting Colorado Plateau with that 

 of Mexico. 



Genl. Char. Smaller than T. fulrus. 



Color. General hue mars brown; dorsal area plumbeous black; 

 feet and tail soiled white ; base of under fur plumbeous. 



Measurements. Total length, 220; tail vertebrae, 66; hind foot, 

 24. Skull: 31.5X22. (Mearns, 1. c.) 



336 martirensis (Thomomys), Allen, Bull. Amer. Mus. Nat. Hist., 



1898, p. 147. 

 SAN PEDRO MARTIR POCKET GOPHER. 



Type locality. San Pedro Martir Mountains, Lower California, 

 Mexico. Altitude, 8,200 feet. 



Geogr. Distr. San Pedro Martir Mountains, Lower California, 

 Mexico. Altitude, 7,000 to 8,200 feet. 



Genl. Char. Larger than T. fiilvus; color less fulvous. 



Color. Upper parts mixed grayish brown and blackish, darkest 

 on median line; side washed with pale fulvous; under parts grayish 

 white; hairs plumbeous at base; around mouth and entrance to 

 cheek pouches dusky ; ear patch blackish ; tail and feet grayish white. 



Measurements. Total length, 248; tail vertebras, 67; hind foot, 

 31. Skull: total length, 44.5; basal length, 41; zygomatic width, 

 25; mastoid width, 21; interorbital constriction, 9; length of nasals, 

 16; width of nasals anteriorly, 5. 



337. aphrastus (Thomomys), Elliot, Pub. Field Columb. Mus., 1903. 

 p. 219. Zoology. 



