94 PEROGNATHUS. 



skull like that of D. simulans with slight variations. Nose-patch not 

 connected with whisker marks. 



Color. General hue pale buff slightly lined with dark hairs; 

 flanks chamois; spot over eye and one behind ears, lips, entire under- 

 parts, stripe over thigh, hands and feet and root of tail white; face 

 in front of eyes creamy white ; tail dark brown above and below ; sides 

 white, tuft dusky. Ex type in United States National Museum. 



Measurements. Total length, 312; tail, 203; hind foot, 45. 

 Skull: Occipito-nasal length, 38.7; Hensel, 23; zygomatic width, 20.9; 

 intertemporal width, 11.5; length of nasals, 13; length of palate, 7.5; 

 length of upper molar series, 5.2; length of mandible, 13.8; length of 

 lower molar series, 5.1. Ex type in United States National Museum. 



Subfamily Heteromyinae. 



Genus Perognathus (98). Pocket Mice. 



Subgenus Perognathus. 



Perognathus fasciatus litus Gary. 



Perognathus fasciatus litus Gary, Proc. Biol. Soc. Wash., XXIV, 

 1911, p. 61. 



Type locality. Sun, Sweetwater Valley, Wyoming. 



Genl. Char. Smaller than T. fasciatus; hind foot slightly larger; 

 color pale. 



Color. Upperparts and flanks cream-buff, slightly lined with black ; 

 underparts pure white; orbital ring and lateral line pale cream-buff; 

 tail above dusky, beneath white; hands and feet white. Ex type in 

 United States National Museum. 



Measurements. Total length, 128; tail, 59; hind foot, 18. Skull: 

 Occipito-nasal length, 22.2; Hensel, 15.6; zygomatic width, 10.2; 

 intertemporal width, 4.7; length of nasals, 7; length of upper molar 

 series, 3.3; length of mandible, 8.6; length of lower molar series, 2.8. 

 Ex type in United States National Museum. 



Perognathus flavescens perniger Osgood. 



Perognathus flavescens perniger Osgood, Proc. Biol. Soc. Wash., 



XVII, 1904, p. 127. 



Type locality. Vermillion, Clay County, South Dakota. 

 Genl. Char. Like P. flavescens in size, and skull, but back black. 

 Color. Head, top and sides mixed black and ochraceous-buff ; 



