125. Large; tail three and onc'half or more inches long; western Louisiana to 



eastern Texas, and northward to Missouri 



Reithrodontomys fulvescens (Allen) Golden Harvest Mouse 

 Smaller; tail less than three and one-half inches long 126. 



126. Tail not distinctly hicolor, grayish below; body usually reddish below; 



in salt marshes along the coast of California 



Reithrodontomys raviventris Dixon Red'bellied Harvest Mouse 

 Tail distinctly bicolor, whitish below; western states 127. 



127. Ears often with one or two dark patches each; rostrum (before eye 



sockets) less than one-third length of skull; S. D. southwards, prefer- 

 ring arid areas 



Reithrodontomys montanus (Baird) Desert Harvest Mouse 

 (Includes R. albescens Gary) 

 Ears usually plain colored; rostrum slightly longer than one-third length 

 of skull; southward and westward from N. D., preferring less sandy 

 areas 



Reithrodontomys megalotis (Baird) Upland Harvest Mouse 



128. Sole of hind foot naked or almost so 129. 

 Sole of hind foot hairy; under parts white 130. 



129. Under parts gray or buffy; total length about four inches; southern 



Texas 



Baiomys taylori (Thomas) Taylor Baiomys 

 Under parts white; total length nine or ten inches; N. J. to the Gulf 

 states 



Oryzomys palustris (Harlan) Rice Rat 



130. Tail shorter than 2.4 in total length; sole of hind foot with four tu' 



bercles; western Minn, to central Oklahoma, and westward 131. 



Tail longer than 2.4 in total length; sole of hind foot with five or six 

 tubercles; generally distributed; Peromyscus Gloger White-footed or 

 Deer mice 



(Intergradation and extreme variation make identification of species 

 very difficult. Only the more common and widely distributed species 

 are included in this key.) 132. 



131. Tail slightly more than one-third of total length; Utah to Galifornia 



and Texas, and southwards into Mexico 



Onychomys torridus (Coues) Coues Grasshopper Mouse 

 Tail one-third or less of total length; western Minnesota south and west 

 Onychomys leucogaster (Wied) Grasshopper Mouse, Scorpion 

 Mouse (Many subspecies) 



132. With five tubercles on sole of hind foot; total length seven and one 



half to nine inches; Florida 



Peromyscus floridanus (Chapman) Florida White-footed 

 Mouse 

 With six tubercles on sole; if from Florida, less than seven and onc'half 

 inches in total length 133. 



133. Ears just the same color as the body; abdomen tinged with the same 



color as the upper parts; southeastern states 



517 



