ONYCHOMYS. 43 



12.4; length of lower molar series, 4.2. Ex type in United States 

 National Museum. 



Onychomys leucogaster breviauritus Hollister. 



Oriychomys leucogaster breviauritus Hollister, Proc. Biol. Soc. Wash., 

 XXVI, 1913, p. 216. 



Type locality. Fort Remo, Oklahoma. 



Genl. Char. Like 0. I. longipes but darker, with shorter tail, 

 smaller hind feet and ears. 



Color. Head and back blackish brown, the color coming from the 

 tips of the hairs, the color of the remaining apical part being pinkish 

 cinnamon; cheeks and flanks paler, hips and lower rump cinnamon; 

 nose gray; spots at base of whiskers cinnamon; underparts, limbs, 

 hands and feet white; tail above grayish brown, beneath white; ear- 

 tufts cinnamon-buff. Ex type in United States National Museum. 



Measurements. Total length, 164; tail, 42; hind foot, 2; ear, 

 13.2. Skull: Occipito-nasal length, 29.5; Hensel, 23.8; zygomatic 

 width, 15.1; intertemporal width, 4.8; width of braincase, 12.5; 

 length of nasals (median), 11.2; length of upper molar series, 4.6; 

 length of mandible, 14.3; length of lower molar series, 4.9. Ex type 

 in United States National Museum. 



Onychomys leucogaster fuscogriseus Anthony. 



Onychomys leucogaster fuscogriseus Anthony, Bull. Am. Mus. Nat. 

 Hist., XXII, 1913, p. ii. 



Type locality. Ironside, Malheur County, Oregon. 



Genl. Char. Smaller than O. leucogaster and the adult pelage 

 darker, more a pale cinnamon-rufous than the ochraceous-buff of the 

 species compared; hind feet smaller. 



Color. Top of head and upperparts dark gray with a slight inter- 

 mixture of pale cinnamon-rufous; sides of head and face paler gray; 

 orbital ring blackish; nose, lips, cheeks, flanks, entire underparts, 

 arms, outer side of thighs pure white; tail above for three-fourths its 

 length paler than the back, more of a pale cinnamon-rufous, remain- 

 ing portion and underpart white; ears very dark gray, almost blackish, 

 with basal tufts and tips white. Ex type in American Museum of 

 Natural History. 



A somewhat older specimen has the head and entire upperparts a 

 pale cinnamon-rufous, both .much darker in color than the upperparts 

 of O. leucogaster, and there is very little of the gray exhibited which 

 is the dominant color of the type of the present species. 



Measurements. Total length, 140; hind foot, 34; tail, 20. Skull: 



