SIGMODON. 227 



Measurements. Total length, 198; tail, 90; hind foot, 25; ear 

 from notch, 18. Skull: total length, 31.5; Hensel, 27.3; length of 

 nasals, 12.5; zygomatic width, 18.3; mastoid width, 13.3; alveolar 

 length of upper molar series, 5.6. 



hispidus in ffsrofensis. 



mascotensis (Sigmodon), Allen, Bull. Amer. Mus. Nat. Hist., 

 1897, p. 54. 



colimce Allen, Bull. Am. Mus. Nat. Hist., 1897, p. 55. 

 MASCOTA COTTON RAT. 



Type locality. Mineral San Sebastian, Mascota, State of Jalisco, 

 Mexico. 



Geogr. Distr. Western portion of State of Jalisco to southern 

 part of State of Oaxaca, Mexico. 



Genl. Char. Larger than 5. h. berlandieri, tail longer, hind foot, 

 larger. 



Color. Above cinnamon brown; sides paler; belly white; hands 

 and feet yellowish gray; tail above dark brown, sides and beneath 

 paler. 



Measurements. Total length, 272; tail vertebrae, 117; hind foot, 

 32. Skull: total length, 34.5; basal length, 30.4; zygomatic breadth, 

 19.5; mastoid breadth, 13.2; interorbital constriction, 4.8; length of 

 nasals, 13.5; length of upper molar series, 6.7. 



hispidus eremicus (Sigmodon), Mearns, Proc. U. S. Nat. Mus., 



1897, p. 504. 

 WESTERN DESERT COTTON RAT. 



Type locality. Cienega Well, Colorado River, State of Sonora, 

 Mexico, thirty miles south of Monument No. 204, Mexican boun- 

 dary line. 



Geogr. Distr. Western Desert Tract, Lower Colorado River, 

 State of Sonora, Mexico. 



Genl. Char. Nasals spatulate at extremity; coloring yellowish 

 instead of grayish. 



Color. Yellowish gray, the sides and rump tinged with ochra- 

 ceous; under surface white; feet grayish white; tail inclined to black- 

 ish above. 



Measurements. Total length, 280; tail vertebrae, 128; hind foot, 

 34; ear, 15. Skull: basal length, 30.6; zygomatic breadth, 20.3; 

 mastoid breadth, 14; length of nasals, 13.3; length of upper molar 

 series, 6.6. 



hispidus berlandieri. 



berlandieri (Sigmodon'}, Baird, Proc. Acad. Nat. Scien. Phila., vn. 



1855. P- 333- 



