NO. 2057. THE GRASSHOPPER MICE—HOLLISTER. 443 



Specimens examined. — Total number, 117, from localities as fol- 

 lows : 



Idaho: Big Lost River, 1; Blackfoot, 6, type and paratypes; 

 Glenn's Ferry, 5; Minidoka, 5; Montpelier Creek, 1; Mm-phy, 1. 



Wyoming: Bear River, 3; Cokeville, 1; Evanston, 6. 



Utah: Kelton, 1; Nephi, 7. 



Nevada: Austin, 7; Battle Mountain, 1; Bull Run Mountains, 1; 

 Carlin, 1; Carson Sink, 1; Cottonwood Range, 1; Elko, 9; Flowing 

 Springs, 1; Gardnerville, 1 (Mus. Comp. Zool.); Golconda, 3 ; Halleck, 

 12; Holbrook, 2 (Mus. Comp. Zool.); Monitor Valley, 1; Mountain 

 City, 4 ; Osobb Valley, 2 ; Pine Forest Mountains, 1 (Univ. of Cali- 

 fornia) ; Pyramid Lake, 3 ; Rabbit Hole Mountains, 2 ; Reese River, 3 ; 

 Silver Creek, 1; Wadsworth, 2; Wells, 1; Winnemucca, 2. 



California: Amedee, 6; Benton, 1 (Univ. of California); Long 

 Valley, 4; Mono Lake, 2; North Hot Springs, Mono County, 1 (Mus. 

 Comp. Zool.); Sierra Valley, 4. 



ONYCHOMYS LETJCOGASTER FUSCOGEISEITS Anthony. 



191^. '$0nycho7nys leucogaster fuscogrisms Anthony, Bull. Amer. Mua. Nat. Hist., 

 vol. 32, p. 11. March 7. 



Type-locality. — Ironside, Malliem- County, Oregon; 4,000 feet 

 altitude. 



Geographic distribution. — Eastern Washington and Oregon, western 

 Idaho, and northeastern Cahfornia. South to Klamath Lake and 

 the Madeline Plains. 



General characters. — Closely related to 0. 1, hrevicaudus, but darker 

 in color; the young especially darker. 



Color. — Similar in aU pelages to 0. I. hrevicaudus, but averaging 

 considerably darker. Adult in summer (88958, Swan Lake Valley, 

 Oregon, June 13): Upperparts dark reddish-brown, rich and glossy; 

 darkest medially, more brownish on sides and hips. Ear tufts con- 

 spicuously whitish; arms white; outer sides of legs to feet color of 

 rump; tail blackish-brown above with grayish-white tip, white 

 below. Yomiger adults vary from dark grayish-brown to rich light 

 pm-phsh-gray. Juvenile (11008, Univ. of Cahf. Mus., Warner 

 Mountains, California, July 28) : Much darker, more blackish, than 

 young of hrevicaudus of same age. Above dark mouse gray, in some 

 lights almost black; legs intensely colored to feet. 



Slcull. — The skuU is essentially as in 0. 1. Irevicaudus. (Plate 15.) 



Measurements. — Averages and extremes of seven adults from 

 Washington, Oregon, and California: Total length, 143 (138-149); 

 tail vertebrae, 38 (34-40) ; hmd foot, 19.2 (18.0-21.0); ear from notch 

 in dry skm, 15.0 (14.5-15.8). Skull: Condylobasal length, 24.9 

 (24.4-25.2) ; zygomatic breadth, 14.1 (12.6-15.0) ; interorbital breadth, 

 4.8 (4.6-5.0); breadth of braincase, 12.7 (12.4-12.9); length of nasals 



