Peromyscus nuttalli (Harlan) Golden Mouse 

 Ears darker than hack, usually edged with whitish; under parts white 



134. 



134. Upper grinding teeth, from side view, not showing small tubercles be 



tween the large ones; no nipples between the fore limbs, two pairs be' 

 tween the hind limbs; west of the Rockies and in western Texas 135. 

 Upper grinders with small tubercles between the large ones; with a 

 pair of nipples between the fore limbs and two pairs between the hind 

 limbs; generally distributed 137. 



135. Total length nine to eleven inches; coast of California 



Peromyscus calif ornicus (Gambel) Parasitic Mouse 

 Total length six and one-half to eight inches 136, 



136. Tail with a distinct tuft of hair at the tip; Oregon to Colorado and 



southwards 



Peromyscus crinitus (Merriam) Canyon Mouse 

 Tail without evident tuft of hair at the tip; Utah to California and 

 Texas, and southwards into Mexico 



Peromyscus eremicus (Baird) Desert Mouse 



137. Sole of hind foot all haired, except the toe pads; generally distributed 



Peromyscus manicuJatus (Wagner) Prairie Deer Mouse 

 (Many subspecies) 

 Distal half of sole of hind foot naked 138. 



138. Hair on under side white to roots; found only in Florida, Georgia and 



Alabama 



Peromyscus polionotus (Wagner) Pigmy Peromyscus 

 Hair on under side darker at roots 139. 



139. Tail usually not over three inches long, or less than onchalf of total 



length 140. 



Tail usually from three to four and one-half inches long, as long as or 



longer than the head and body 141. 



140. Not found north of southern Virginia and southern Illinois; tail not 



distinctly bicolor 



Peromyscus gossypinus (Le Conte) Cotton Mouse 

 From Canada to Louisiana; tail distinctly bicolor 



Peromyscus leucopus (Raf.) Forest Deer Mouse 



141. Tail about equal to head and body; eastern Oklahoma and Texas east 



to the Atlantic; southern 111. and Virginia southwards 



Peromyscus gossypinus (Le Conte) Cotton Mouse 

 Tail slightly longer in proportion to head and body; Arkansas to Cali' 

 fornia; Oregon to Mexico 142. 



142. Ear large, as long as hind foot 



Peromyscus truei (Shufeldt) Big-eared White-footed Mouse 

 Ear smaller, not as long as the hind foot 143. 



143. With dusky markings on "ankle" or tarsal joint 



Peromyscus hoylii (Baird) Boyle White-footed Mouse 

 No dusky markings on tarsal joint 



Peromyscus pectoralis (Osgood) Lacey White-footed Mouse 



518 



