32 Proceedings of the Biological Society of Washington. 



typical consobrinus and strikingly different from the buffy and gray under 

 surface of tails of minimus and pictus ; median dorsal stripe clear black 

 and reaching from crown to base of tail ; two pairs of lateral dark stripes 

 brownish black ; two outer light stripes white or whitish; two inner light 

 stripes clear gray; throat white; belly buffy. 



Measurements. — Type specimen : Total length, 190; tail vertebrae, 85; 

 hind foot, 31 ; an adult c? from Snow Pass, only two miles from type 

 locality, 198; 88; 32. Skull. — Basal length, 25; zygomatic breadth, 16; 

 mastoid breadth, 15; nasals, 8; alveolar length of upper molar series, 4.5. 



Remarks. — This is merely a pale valley form of E. consobrinus which 

 superficially resembles pictus, and has no connection with the larger, 

 yellow pallidus lower down the Yellowstone Valley in Montana. 



