196 PEROMYSCUS. 



Genl. Char. Body stout ; ears very large ; tail longer than the body. 



Color. Above mixed glossy brown and pale yellowish brown; 

 hands, feet, and lower parts white ; white on sides bordered by a line 

 of reddish buff, which grades into the color of the upper parts; tail 

 above dusky, beneath white. 



Measurements. Total length, 195; tail vertebrae, 101; hind foot, 

 23; ear, 22. Skull: occipito-nasal length, 29; Hensel, 22; zygomatic 

 width, 14; interorbital constriction, 4; length of nasals, n; palatal 

 length, ii ; length of upper molar series, 4. 



*a. penicillatus (Peromyscus*), Mearns, Proc. U. S. Nat. Mus., 



1896, p. 139. Elliot, Syn. N. Am. Mamm., 1901, p. 133. 

 FRANKLIN MOUNTAINS MOUSE. 



Type locality. Franklin Mountains, near El Paso, El Paso 

 County, Texas. 



Geogr. Distr. Texas, probably into State of Chihuahua, Mexico. 



Genl. Char. Nasal bones of skull truncate posteriorly, and 

 ending in front of the posterior ends of premaxillae. 



Color. Above drab gray tinged with ochraceous buff on rump 

 and sides; hands, feet, and under parts pure white; tail dusky drab 

 above, white below. 



Measurements. Total length, 202; tail vertebrae, 115; hind foot, 

 22 ; ear, 14. 



160a. polius (Peromyscus} , Osgood, Proc. Biol. Soc. Wash., xvn, 



1904, p. 61. 

 GRIZZLED MOUSE. 



Type locality. Colonia Garcia, State of Chihuahua, Mexico. 



Genl. Char. Similar to P. boylii rowleyi, but larger and grayer. 



Color. Upper parts grayish broccoli brown; lateral line pinkish 

 buff; orbital ring dusky; under parts white; tail bicolor; hands, feet, 

 and ankles white. 



Measurements. Total length, 210-234; tail vertebras, 111-120; 

 hind foot, 25-26. Skull: greatest length, 29.9; Hensel, 22.9; zygo- 

 matic width, 14.8; interorbital constriction, 4.5; interparietal, 

 10.5x2.8; length of nasals, n.6; palate, 4.4; postpalatal length, 10; 

 length of upper molar series, 4.7. 



161. gratus (Peromyscus}, Merr., Proc. Biol. Soc. Wash., x, 1898, 



p. 123. 

 TLALPAM FIELD MOUSE. 



Type locality. Tlalpam, Valley of Mexico. 



* Dr. E. A. Mearns informs me that this mouse has been taken within a mile 

 of the Mexican border. 



