356 PEROGNATHUS. 



Genl. Char. Similar to P. bimaculatus , but smaller; tail more 

 hairy; lower premolar more nearly quadrate; audital bullae more 

 separated. 



Color. Above pale ochraceous drab, lined with black; ears and 

 spot at base of whiskers blackish; orbital area pale buff; spot behind 

 eye and also the lateral line on body pale buff; feet and under parts 

 white; tail hoary at base, tip dusky. 



Measurements. Total length, 109; tail vertebrae, 53; hind foot, 

 15.5; ear from crown, 4.7. Skull: length of Hensel, 13; occipito- 

 nasal length, 19; greatest mastoid breadth, n; length of inter- 

 parietal, 2.2; greatest width of interparietal, 3.44 interorbital con- 

 striction, 4.9; length of nasals, 7. 



apache melanotis (Perognathus) , Osgood, N. Am. Faun., No. 18, 1900, 



p. 27. 

 BLACK-EARED POCKET MOUSE. 



Type locality. Casas Grandes, State of Chihuahua, Mexico. 



Geogr. Distr. Known only from type locality. 



Genl. Char. Similar to P. apache, but darker, smaller. 



Color. Above rich buff, lined with black; under parts pure 

 white; orbital region buff; ears, edges, and spot at base white; inside 

 black; tail above dusky, beneath buffy white. 



Measurements. Total length, 133; tail vertebrae, 65; hind foot, 

 19.5. Skull: length of Hensel, 15.3; occipito-nasal length, 21.5; 

 greatest mastoid width, n.8; length of interparietal, 2.8; greatest 

 interparietal width, 4.3; interorbital constriction, 5; length of 

 nasals, 8. 



B. Ohsetodipus. 



"Mastoids moderately developed, not projecting behind plane 

 of occiput; interparietal broadly pentagonal, or strap-shaped; mas- 



FIG. 68. PEROGNATHUS (CH/ETODIPUS) FEMORALIS MESOPOLIUS. 



No. 10374 Field Columbian Mus. Nat. size. 



Tooth rows enlarged q times. 



