27. Tail with a black tip; in the Great Plains 



Cynomys ludovtcianus (Ord) Black-tailed Prairie Dog 

 Tail with a white tip 28. 



28. Distal half of tail gray, edged with white; southern Rockies into Colo. 



Cynomys guyinisom (Baird) Gunnison Prairie Dog 

 Distal half of tail white; northern Rockies into Colo. 



Cynomys leucurus Merriam White-tailed Prairie Dog 



29. With definite stripes on back and sides 30. 

 No definite color stripes, except sometimes a mid-dorsal stripe or band 43. 



30. With lengthwise stripes on the sides of the head 31. 

 No definite stripes on the sides of the head 38. 



31. Mid-dorsal stripe bordered on each side by a much wider band; with 



four upper grinding teeth on each side; eastern and central states 

 Tamias stnatus (Linn.) Eastern Chipmunk 

 Mid-dorsal dark stripe bordered on each side by a lighter stripe of about 

 equal width; with five upper grinding teeth on each side; west of the 

 Mississippi, except in the northern states, where it spreads into Wis. 

 and Michigan Western Chipmunks 32. 



32. Light spot behind ear indistinct or grayish 33. 

 With a white spot behind each ear 34. 



33. Stripe through eye and edges of ears black; northern Rocky Mountain 



area and Pacific states 



Eutamias amoenus (Allen) Klamath Pine Chipmunk 

 Stripe through eye and ears brown; in the Cal. coastal ranges 

 Eutamias mernami (Allen) Merriam's Chipmunk 



34. Stripe through eye brown; edges of ears grayish; small, about seven 



inches in total length; generally distributed over the western and 

 northern states to Michigan 



Eutamias minimus (Bachman) Little or Sagebrush Chipmunk 

 Stripe through eye black or blackish; larger 35. 



35. Large, about ten inches in total length; edges of tail whitish; hairs on 



backs of ears banded with two or three colors; Pacific states 36. 



Smaller, about eight to nine inches; edges of tail buffy 37. 



36. With a black stripe below the ear; white spot behind ear as long as ear; 



Cal. and Nevada 



Eutamias quadrimaculatus (Gray) Long-eared Chipmunk 

 With a reddish-brown stripe below the ear; white spot behind ear smaller 

 than ear; Pacific states 



Eutamias townsendii (Bachman) Townsend's Chipmunk 



37. Crown and shoulders gray; not much black in stripes; Rocky Mountain 



states west to the Sierras 



Eutamias quadrivittatus (Say) Say's Chipmunk 

 Crown and shoulders brown; with definitely black stripes on body; Cal. 

 into Nevada 



Eutamias speciosus (Merriam) Lodgepole Pine Chipmunk 



507 



