PEROMYSCUS. 175 
PAGE 
gee bove inlvous Drown... .0. 2)... 2.5: P. z. cristobalensis 209 
r.’ Rostrum elongated, bullz small. . 
a.’’ Above fulvous chestnut and black...... P. megalops 210 
b.’”” Smaller and darker. 
2 ioe Males Gr Eaat a! 2) (0) 2 a a en P. melanocarpus 210 
b.’” Tail with white line beneath........ P. altilaneus 210 
ee Above blackish pray... ¢0 5.05.4. P. guatemalensts 211 
me eabove sooty DOWD. ..-)24. 030.2. oes P.cacabatus 211 
b. Tail nearly two-thirds the length of head and 
EES OLS ad ees P. mecisturus 212 
127. tiburonensis (Peromyscus), Mearns, Proc. U. S. Nat. Mus., 
1897, Pp. 720. 
IsLAND OF TIBURON MOUSE. 
Type locality. Tiburon Island, Gulf of California, Mexico. 
Geogr. Distr. Known only from type locality. 
Genl. Char. Size very small; ears nearly naked. 
Color. Upper parts drab gray and black; sides ochraceous cin- 
namon; under parts white; tail blackish brown; hands and feet 
white; ears dark brown. 
Measurements. Total length, 175; tail vertebre, 85; hind foot, 
19; ear, 16. Skull: total length, 24; greatest width, 12. (Mearns, 
1G) 
*127a. allex (Peromyscus), Osgood, Proc. Biol. Soc. Wash., xvi, 
1904, p. 76. 
Dwarr Mouse. 
Type locahty. Colima, State of Colima, Mexico. 
Genl. Char. Like P. musculus, but smaller; nasals short; bulle 
very small. 
Color. Exactly like P. musculus. 
Measurements. Total length, 113; tail vertebre, 47; hind foot, 
14; ear from notch, 9.7. Skull: greatest length, 18.4; Hensel, 14.6; 
zygomatic width, 9.6; interorbital constriction, 3.2; length of nasals, 
6.3; interparietal, 5.5 x 1.3; palate, 3; length of upper molar series, 3. 
128. musculus (Sztomys), Merr., Proc. Biol. Soc. Wash., vit, 1892, 
p. 170. 
Cotrma City Mouse. 
Type locality. Near Colima City, State of Colima, Mexico. 
Geogr. Distr. States of Colima and Jalisco, Mexico. 
Genl. Char. Similar to P. taylort, but lighter and larger. 
*Descriptions of numerous forms of Peromyscus by Mr. Osgood (1. c.) were 
published too late to be included here in their regular numerical order. 
