1916.] 



CYNOMYS PAEVIDENS. 



27 



although tjiere was no natural barrier. Gary found them intermin- 

 glmg in colonies near Ishawooa, Wyoming, and Bailey captured a 

 specimen of leucurus in a ''town" of ludovicianus in Clark's Fork 

 valley, Montana. 



Except for what appears to be a sHght average increase in size in 

 the extreme southern portions of its range, the specimens of C. 

 leucurus that have been assembled present a remarkably uniform 

 appearance, both in coloration and in skull characters. There- has 

 been considerable misunderstanding in times past as to the western 

 limit of distribution of this species. Many writers beheved that 

 its range extended to the Plains of the Columbia, and this mistake 

 is one of the principal reasons for past confusion in nomenclature. 

 As a matter of fact the animal is entirely unknown in Idaho, and 

 crosses the Bear River Divide to the Wyoming-Utah boundary at 

 only one place, so far as known. Regarding this western Hmit of 

 distribution, Dr. Merriam has given me an interesting note. He tells 

 of tracing the species, in 1913 and 1914, across the Utah- Wyoming 

 boundary not far from Evanston, westward into Utah for a distance 

 of six or seven miles where it stops abruptly. 



Specimens examined— TotoX number, 107, as follows: 

 Colorado: Beaver Creek to bridge over White Elver (Rio Blanco County), 2;i'2 

 Big Beaver Creek, 2;^ Buford, 1; Canadian Creek, 2; Coyote Basin, l;i 

 Craig to Kelly's (Moffat County), 4;^ Crawford, 1;^ Douglas Spring, 1;^ 

 Escalante HiUs, 1; Grand Junction, 17; Hayden, 1; Hebron, 1; HeU Creek 

 (Jackson County), 1;^ Meeker, 4; North Park, 1; Sand Creek to Snake River, 

 2.i»2 



Montana: Clark's Fork, 1; Sage Creek, 2. 



Utah: Uinta Mountains, 1;^ Uncompahgre Indian Reservation, S.^ 

 Wyoming: Bear Creek, 1; Bighorn Basin, 1; Big Piney, 1; Big Sandy, 1; Brid- 

 ger's Pass, 1; Cheyenne (west of), 2; Cumberland, 2; Deer Creek, 2; Dubois, 

 1; Fontenelle, 1; Fort Bridger, 10 (including type); Fort Steele, 2; Fossil, 

 1; Garrett, 2; Green River, 2; Independent Rock (25 miles southwest of), 

 1; Ishawooa, 1; Lander, 3; Laramie Mountains, 2; Lost Cabin, 1; Medicine 

 Bow Mountains, 4; New Fork of Green River, 6; Otto, 1;^ Pole Creek, 1; 

 Shirley Mountains, 1; Spring Creek, 1; Sweetwater, 1; Woods Post Office, 5. 



CYNOMYS PARVIDENS Allen. 



Utah Prairie-Dog. 



(PI. Ill, fig. 2; PI. IV, fig. 2; PI. V, fig. 4; PI. VII, fig. 4.) 



1905. Cynomys parvidens Allen, Science Bull., Mus. Brooklyn Inst. Arts and Sci., 

 I, no. 5, p. 119, March 31. 



Type locality. — Buckskin Valley, Iron County, Utah. 

 Geographic distrihution. — ^Mountain valleys of central Utah in the 

 Sevier River region; south from Nephi to Iron and Garfield Counties. 



1 Collection E. R. Warren. 2 Collection Amer. Mus. Nat. Hist. ^ Collection Mus. Comp. Zool. 



