90 Cary Identity of Eutamias pcdlidus (Allen). 



Corral Draw (near Sheep Mountain) 12 (Coll. Am. Mus. Nat. Hist., W. W. 

 Granger) ; Cheyenne River Bad Lands 12, and " Mauvaises Terres " 1 (Coll. 

 U. S. Nat. Mus., L. Stejneger and F. V. Hay den, respectively) ; Sheep 

 Mountain 7 (Biol. Surv. Coll., Merritt Cary). 



Remarks. So far as at present known, this beautiful chipmunk, which is 

 by far the palest member of the genus, occurs only in the Big Bad Lands 

 of western South Dakota, and the Hat Creek Basin Bad Lands of extreme 

 northwestern Nebraska* the Mauvaises Terres of the French voyageurs. 

 The extreme pallor of coloration is manifestly due to environment. The 

 white, alkaline soil, which supports scarcely a vestige of vegetation over 

 large areas, exerts a strong bleaching effect upon the few mammals re 

 stricted to the Bad Lands. The most marked instance of this among 

 mammals, aside from chipmunks, is Neotoma rupicola, the palest wood-rat, 

 which occurs only among the Bad Lands. 



* While collecting in the Hat Creek Basin in 1901, the writer often saw very pale 

 chipmunks in the Bad Lands of that region, but unfortunately collected no specimens. 



