FIELD BOOK OF MAMMALS 



reported as formerly existing, in Sac County and at Burling- 

 ton, Iowa; near Monroe, Louisiana; at Seneca, South 

 Carolina; and on Nantucket Island, Massachusetts." 

 (HoUister) 

 Arizona Prairie-dog. — Cynomys ludovicianus arizonensts 

 (Mearns). •.•1.1 



Slightly larger than typical ludovicianus and more brightly 

 colored. Found in "Southeastern Arizona, southern and 

 central New Mexico, southwestern Texas, and adjacent 

 portions of Sonora and Chihuahua, Mexico. North to San 

 Pedro and Santa Rosa, New Mexico; east to the Pecos 

 Valley; west to Huachuca, Arizona; south to San Diego and 

 Casas Grandes, Chihuahua, and to Presidio County, 

 Texas." (HolHster) 



Subgenus Leucocrossuromys 



White-tailed Prairie-dog. — Cynomys leucurus Merriam. 

 Plate XX. 

 More like a Ground Squirrel (Citellus) m appearance than 

 the forms of ludovicianus. Tail less than one-fifth of the 

 total length, tipped with white instead of black, hving more 

 in the mountains than ludovicianus, which is a plains type. 

 Color, above, buffy streaked with blackish, dark brown spots 

 above the eye and on cheek; below, clear buffy. Tail clear 

 white for terminal half, white banded with blackish above 

 for first half. Total length, 13.5-14.8 inches; tail vertebras, 

 1.8-2.4 inches; hind foot, 2.4-2.6 inches. Found m "Ir- 

 regular areas in the mountainous parts of Montana, Wyom- 

 ing, Utah, and Colorado. South from the Bighorn Basm, 

 in southern Montana, across central and southwestern 

 Wyoming into western Colorado and northeastern Utah; 

 Utah east to the Laramie Mountains, Wyoming, and into 

 North Park, Colorado; south into the lower Gunnison 

 Valley; west a few miles across the Bear River Divide into 

 extreme northern Utah and, farther south, into the Green 

 River Valley. Chiefly Transition Zone." (Hollister) 

 Utah Prairie-dog. — Cynomys parvidens Allen. 



Closely resembling leucurus but redder and less buffy above, 

 smaller. Upperparts (summer) cinnamon. Total length, 

 12,2-15.4 inches. Found in "Mountain valleys of central 

 Utah in the Sevier River region ; south from Nephi to Iron 

 and Garfield Counties." (Hollister) ^ w-n • jn 



Gunnison Vraxrie-Aog.— Cynomys gunnisoni gunnisoni (Baird). 

 Resembling leucurus but darker, with less buffy and less 

 sharply marked on cheeks; tail with less white, more like 

 back for first half of its length. Total length, 12.2-14.6 

 inches. Found in "Rocky Mountain region of central and 

 central-southern Colorado and northern New Mexico. 

 North into South Park. Colorado; east to El Paso, Fremont, 

 and Huerfano Counties, Colorado; south into the Sangre de 



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