AMERICAN FROGS OF THE GENUS RANA. 453 



jof the snout; distance between the nostrils usually greater than the 

 interorbital Avidth, which equals f to f that of the upper eyelid; 

 tympanum more or less distinct, f to f the diameter of the eye, 1| to 

 2 times its distance from the latter. 



Fingers moderate, obtuse or rather pointed, first longer than second, 

 third usually longer than the snout; subarticular tubercles moderate. 



Hind limb moderately long, the tibio-tarsal articulation reaching 

 the tympanum or the eye, the heels meeting or slightly overlapping 

 where the limbs are folded at right angles to the body; tibia 3 to 4| 

 times as long as broad, 2 to 2i times in length from snout to vent, 

 shorter than the fore limb, shorter than the foot. Toes obtuse, f to 

 nearly entirely webbed, one or two phalanges of fourth free, the web 

 thicker and with convex border in the breeding male; the web extend- 

 ing about half way between the outer metatarsals; subarticular 

 tubercles small, moderately prominent; no tarsal fold; inner meta- 

 tarsal tubercle oval, j to ^ the length of the inner toe; a small, round, 

 or conical outer tubercle usually present. 



Upper parts smooth or with small warts; pearl-like horny tubercles 

 often present on the body and hind limbs; a moderately broad and 

 moderately prominent glandular dorso-lateral fold from above the 

 tympanum to the hip; the dorso-lateral folds parallel or slightly 

 converging towards each other on the scapular region, where they 

 are separated from each other by a space contained 4| to 6 times in the 

 length from snout to vent. Lower parts smooth. 



Brown, yellowish, or reddish above, with small darker spots which 

 may have light centers and often with more or less profusely scattered 

 ink-black spots on the back; flanks with large dark spots or marblings; 

 a dark streak from the tip of the snout to the eye and a more or less 

 marked dark temporal spot; a light streak from below the nostril to 

 above the arm; limbs usually with more or less regular dark cross- 

 bands. Lower parts wliite, uniform or mottled or marbled with gray; 

 in life salmon-red on hind limbs and in a more or less conspicuous 

 U-shaped marking on the belly. 



Male without vocal sacs, with very strong fore limbs and a large pad 

 on the inner side of the first finger. 



Skeleton similar to that of R. temporaria. 



The tadpole has not been described, but the eggs are known to be 

 very similar to those of R. temporaria, nearly entirely black and 

 nearing 2 to 2| millimeters in diameter. 



Habitat. — North America, from the Rocky Mountains westwards, 

 from British Columbia to California. 



