Ranidae 



THE WESTERN FROG 

 Rana pretiosa Baird and Girard 



Identification Characteristics 



Colour: Variable; dull or bright yellowish or reddish brown 

 on head, back, and upper surfaces of arms and legs. Few or 

 many irregular, roundish black spots — like splashes of ink — 

 on the back between the lateral folds. Lower sides light yel- 

 lowish grey, unspotted. Underparts light, obscurely or con- 

 spicuously marbled with greyish brown. Salmon-red on under- 

 surfaces of legs, and in a more or less conspicuous U-shaped 

 marking on the belly. A light glandular streak from under the 

 eye to the arm, interrupted at the end of the jaw. Iris bright 

 yellow, not orange-coloured or bronze. (See Colour Plate XVI.) 



Measurements: Size medium, i. e. male 2 to 3 inches; female 

 3 to 4 inches in length. Leg to the heel as long as the body 

 (i. e. forward to the ear). Foot conspicuously longer than lower 

 leg. (Figs. 260 and 262, also Colour Plate XVI.) 



Structure: The skin is everywhere rough, even in the region 

 of the ear. Lateral folds distinct. Head rounded, broader 

 than long. Ear smaller than the eye. Head not conspicuously 

 angled along the lines between eyes and nostrils. Nostrils 

 round. Eye not large, set obliquely, so as to be but slightly 

 elevated, and so as to face more dorsalwards than is usual. 

 The foot has broad webs extending to the tips of all the toes, 

 except the fourth, which has the short terminal joint free. (Fig. 

 260.) The whole lower surface of the foot, as well as the but- 

 tocks and outer surfaces of legs (especially of lower leg), very 

 rough with crowded tubercles. The inner tubercle of the foot 

 is small, and there is a small tubercle opposite this on the sole. 

 (Fig. 263.) 



Range: Northwestern North America, as far east as the 

 foot of the Rocky Mountains in Montana, north to Puget Sound, 

 and south to southern California. 



The Western Frog has been found during the winter, sleep- 

 ing in the mud under a foot or more of water, along marshy lake 



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