238 PERODIPUS. 



Geogr. Distr. Elevated Central Tract, Arizona. 



Genl. Char. More slender than F. ordi; tail longer and color 

 darker. Skull lighter, smaller. 



Color. Above mouse gray mixed with black and buff; sides sandy 

 buff; usual white line on side of nose, white ear and eye spots, and 

 thigh stripe; under parts white. Dorsal and ventral stripes drab 

 gray; lateral white stripes extending to near end of vertebrje. 



Measurements. Total length, 280; tail vertebra;, 148; hind 

 foot, 38. 



360. ordi. {Dipodomys), Woodh. Proc. Acad. Nat. Scien. Phil., 



1853. P- 235. 



Type locality. El Paso, Rio Grande, Texas. 



Geogr. Distr. From Snake Plains and their northward exten- 

 sions south to New Mexico and Arizona. 



Genl. Char. Size medium; tail little shorter than head and body. 



Color. Above ochraceous buff, darkest on back mixed with 

 black on rump; sides paler; side of nose, spot behind the ear, stripe 

 across thigh and under parts white. Tail with dorsal and ventral 

 stripes dusky, base of hairs white. 



Measurements. Total length, 240; tail vertebra, 134; hind foot, 

 38; ear 7. 



a. — colwmbianus. (Ferodipus), Merr. , Proc. Biol. Soc. Wash., 1894, 

 p. 115. 



Type locality. Umatilla, Oregon. 



Geogr. Distr. Plains of the Columbia, Oregon. 



Genl. Char. Similar to F. ordi, but paler; ears blackish. 



Color. Above clay color mixed with blackish; thigh patches and 

 inner side of leg tinged with ochraceous; interior and upper border of 

 ear blackish; beneath white; dusky stripes on upper and under side 

 of tail; lateral white stripes nearly meeting towards end of tail, tip 

 dusky. 



Measurements. Total length, 244.5; tail vertebrae, 140.5; hind 

 foot, 39. 



361. richardsoni. (Dipodops), Allen, Amer. Mus. Nat. Hist., i8gi, 



p. 277. 



Type locality. Beaver River, Indian Territory. 



Geogr. Distr. Oklahoma and Indian Territories. 



Genl. Char. Similar to F. ordi, but larger. Skull: rostrum 

 robust; intermastoid area quadrate, lateral borders slightly concave, 

 anterior border longer than posterior. 



Color. Above ochraceous huff, lined with black; sides paler; 

 legs outside to heels like sides of body; beneath white, as is also the 



