22 



NORTH AMEEICAN FAUNA. 



[No. 36. 



EemarTcs,— This subspecies is a slightly differentiated race of 

 humulis, with, which it is connected by a complete series of inter- 

 grades. Indeed; occasional specimens of Jiumulis from localities 

 within the range of the typical race are difficult to distinguish from 

 merriami. The differences are perhaps most evident on comparing 

 individuals of the two forms in worn pelage, merriami being in that 

 condition decidedly sooty, while Jiumulis is a warm brown. Three 

 specimens from Lexington, Ky., seem referable to this subspecies, 

 but one from Ceredo, in the extreme western corner of West Virginia, 

 is intermediate in color between merriami and Jiumulis. 



Specimens examined. — Total number, 37, from the following locali- 

 ties: 



Texas: Austin Bayou near Alvin, 8; Richmond, 2. 

 Lomsiana: Hackley, 1; Lafayette, 3; Mermenton, 3.^ 

 Alabama: Barachias, 5; Carlton, 1; Dean, 1; Jackson, 2; York, 7. 

 Kentucky: Lexington, 3. 

 West Virginia: Ceredo, 1. 



REITHRODONTOMYS ALBESCENS ALBESCENS Cary. 



Pallid Harvest Mouse. 



(PI. I, fig. 4; PL IV, fig. 4.) 



Reithrodontomys albescens Cary, Proc. Biol. Soc. Wash., XVI, 1903, p. 53. 

 Reithrodontomys montanus albescens Cary, N. Am. Fauna No. 33, 1911, p. 110. 



Type locality. — Eighteen miles northwest of Kennedy, Nebr. 



Distribution. — Sand-hill region of Nebraska and western South 

 Dakota; west to Loveland, Colo. 



CJiaracters. — Similar to R. montanus, but paler, with a more dis- 

 tinct dorsal stripe; ears smaller; skull shorter and broader. 



Color. — Unworn winter pelage (NoYcmber) : Upperparts mixed 

 blackish and light buff, darkest on the median line and shading to 

 pure buff on the sides ; ears buffy, usually with two rather large brown- 

 ish or blackish patches; tail sharply bicolor, dark hair-brown above, 

 white below; feet soiled whitish; underparts pure white. Worn 

 summer pelage (October): Upperparts mixed ochraceous-buff and 

 blackish, the buff prevailing, shading to light ochraceous-buff on sides. 

 A gray phase occurs in which the upperparts are mixed blackish and 

 pale mouse-gray, with very slight admixture of buff. 



SJcull. — Shorter and relatively broader than that of montanus; 

 rostrum short and heavy; zygomata heavy and widely expanded. 



Measurements. — Average of 6 adults from Nebraska: Total length, 

 125 (121-129); tail vert ebrge, 53.4 (50-56); hind foot, 16.7 (16.5-17). 

 Skull (see table, p. 81). 



Remarlcs. — This handsome mouse is the palest member of the genus. 

 According to Cary it occurs only in sand-hills or on sandy land. At 



1 Collection Field Mus. Nat. Hist. 



