Snout less acute; length about three times the length of the head; if a 

 white marking is present on the tympanum, this is typically a blotch 

 and not a definitely rounded spot; widely distributed (For a discussion 

 of the R. pipiens complex, see Wrights' HANDBOOK, page 498.) 

 Rana pipiens pipiens Schreber Meadow or Leopard Frog, 



Grass Frog 

 (Rana virescens of Cope) 



84. Web on hind foot very broad, extending to the ends of the toes except 



the fourth, which may have one joint free; dorsolateral folds often ob' 

 scure or absent 85. 



Web more moderate, extending not farther than the second joint of the 

 fourth toe (excepting a very narrow line of web parallel with the sides 

 of the toe, which may extend slightly farther) ; dorsolateral folds entire 



90. 



85. Under parts white, except for dark clouding on the throat and a touch of 



yellow on the hind feet; Ari2;ona and N. M. 



Rana tarahumarae Boulcngcr Mexican Frog 

 Under parts yellow or red posteriorly; throat or breast often spotted or 

 mottled 86. 



86. Length of leg to heel extending forward to the eye; tympanum smooth; 



usually with a light line along the upper jaw, with or without dark 

 mottling; under parts orange to red posteriorly 87. 



Length of leg to heel extending forward about to the nostril; tympanum 

 often with small tubercles; upper jaw usually conspicuously mottled; 

 under parts yellow posteriorly 88. 



87. Spots on the back about the size of the eyes; upper jaw practically plain, 



except for the light line; with two tubercles on the sole of the hind 

 foot; Montana to Arizona, and westward 



Rana pretiosa pretiosa B. & G. Western Red-legged Frog 

 (Rana temporana pretiosa of Cope) 

 Spots on back usually smaller and more numerous; upper jaw much spot- 

 ted and mottled, and v/ith a light line; with one tubercle on the sole of 

 the hmd foot; Nevada into Oregon and Idaho 



Rana pretiosa luteiventris Thompson Nevada Red'legged Frog 



88. With a light spot on top of the head; Oregon and Cal. 



Rana boylii hoylii Baird Western Yellow-legged Frog 

 Not so 89. 



89. Tympanum with many small tubercles; Cal. 



Rana boylii mucosa Camp California Yellow-legged Frog 

 Tympanum scarcely tubercular; Cal. and Nevada 



Rana hoylii sierrae Camp Sierra Yellow-legged Frog 



90. Upper jaw almost uniformly colored; skin of back smooth; Nevada 



Rana fisheri Stejneger Nevada Spotted Frog 

 (Rana onca Cope) 

 Upper jaw conspicuously spotted or mottled with dark; skin of back 

 usually somewhat tubercular 9L 



9L With many small dark spots on the throat region; dark spots on back 

 (about size of eye) irregular in shape and scarcely light bordered 92. 



355 



