SIGMODON. 229 
breadth, 16.4; alveolar length of upper molar series, 7.3. (Bailey, 
ec.) 
hispidus tonalensis (Sigmodon), Bailey, Proc. Biol. Soc. Wash., xv, 
TGO2, p.. 109. 
TonaLaA Cotton Rat. 
Type locality. Tonala, State of Chiapas, Mexico. 
Geogr. Distr. Eastern part of State of Oaxaca, into western part 
of State of Chiapas. 
Genl. Char. Similar to S. mascotensis, but larger. 
Color. Above yellowish. brown; beneath creamy white; feet and 
tail dull brownish gray. 
Measurements. Total length, 350; tail, 166; hind foot, 41. 
Skull: basal length, 34.5; nasals, 15; zygomatic breadth, 22; mastoid 
breadth, 14.5; alveolar length of upper molar series, 6.8. 
Fic. XXXVIII. SIGMODON H. INEXORATUS. OCOTLAN COTTON Rat. 
hispidus inexoratus (Sigmodon), Eliot, Pub. Field Columb. Mus., 
III, 1903, p. 144. Zodlogy. 
OcoTLaN CoTTon Rat. 
Type locality. Ocotlan, State of Jalisco, Mexico. 
Genl. Char. Size large. Skull with infraorbital foramina oblong 
and narrow; frontal region broad. 
Color. Above mixed creamy buff and black; sides paler cream 
buff, as are also the arms, hands, and thighs; hind feet gray; under 
parts grayish white; tail nearly naked, blackish above, whitish 
beneath; ears dark brown or blackish. 
Measurements. Total length, type, 310; tail vertebra, 146; 
hind foot, 36. Skull: total length, 37; Hensel, 31; zygomatic width, 
20; mastoid widthw15; median palatal length, 8; length of incisive 
foramen, 7; upper tooth row, 7; lower tooth row, 7. 
