226 SIGMODON. 



occipito-nasal length, 35.8; zygomatic width, 20.4; length of palate 

 to palatal notch, 16.2; length of upper molar series, 6; length of 

 single half mandible, 20. 



hispidus t-oltecus. 



toltecus (Hesperomys), Sauss., Rev. Mag. Zool., 2me Se"r., 1860, p. 



98. 

 TOLTEC COTTON RAT. 



Type locality. "Cordilleras of Vera Cruz," Mexico. 



Geogr. Distr. Alta Mira, State of Tamaulipas, southward to 

 Orizaba, State of Vera Cruz, Mexico. 



Genl. Char. Tail rarely equaling head and body; similar to 

 S. hispidus; soles and tail naked. 



Color. Above mixed black and yellowish brown; flanks paler, 

 the brown color predominating; chin and under parts grayish white; 

 tail bicolor, above blackish, paler beneath; feet grayish brown. 



Measurements. Total length, 207-235; tail, 100-146; hind foot, 

 17-28. Skull: basal length, 32; zygomatic breadth, 21; mastoid 

 breadth, 15; length of nasals, 14; length of upper tooth row, 6.7. 



hispidus rnicTodon (Sigmodon), Bailey, Proc. Biol. Soc. Wash., xv, 



1902, p. in. 

 SMALL-TOOTHED COTTON RAT. 



Type locality. Puerto Morelos, Yucatan. 



Geogr. Distr. Northern Yucatan, and State of Campeche, Mexico. 



Genl. Char. Size small; teeth small; tail short. 



Color. Above dark dull brown; beneath grayish white or buffy; 

 tail above black, beneath brownish. 



Measurements. Total length, 243; tail, 96; hind foot, 32. Skull 

 of type: basal length, 28.4; nasals, 12.5; zygomatic breadth, 18; 

 mastoid breadth, 13; alveolar length of upper molar series, 5.5. 

 (Bailey, 1. c.) 



hispidus baileyi. 



baileyi (Sigmodon), Allen, Bull. Am. Mus. Nat. Hist., 1903, p. 601. 

 BAILEY'S COTTON RAT. 



Type locality. La Cienega de las Vacas, State of Durango, 

 Mexico. Altitude, 8,500 feet. 



Genl. Char. Similar to S. h. major, but smaller. 



Color. Upper parts gray brown, sides tinged with buff, with the 

 long hairs tipped with white or black; under parts white, basal part 

 of hairs plumbeous; side of nose .ochraceous buff; base of tail suffused 

 with cinnamon buff; feet pale buffy gray; tail blackish brown above, 

 pale buffy gray beneath; ears dark gray. 



