428 BOULENGER. 



Habitat. — North America, east of the Rocky Mountains, from Can- 

 ada (Quebec and Ontario) to Florida and Louisiana. 



5. Rana onca. 



Rana onca Cope, in Yarrow, Rep. Explor. Surv. w. of 100th Mer., Batr. 

 Rept., p. 528, PL xxv, figs. 1-3 (1875); Dickerson, Frog Book, p. 196, PI. ii, 

 fig. 6 (1906) ; BotjLENG., Ann. and Mag. N. H. (9), III, 1919, p. 409. 



Rana draytoni onca Cope, Batr. N. Am., p. 443 (1889). 



Ranafischeri Stejneg., N. Am. Faun., No. 7, p. 227, PI. in, fig. 5 (1893). 



Vomerine teeth in small groups close together between the choanse 

 or extending a little beyond the level of their posterior borders. 



Head as long as broad or broader than long, rather strongly 

 depressed; snout rounded, feebly projecting beyond the mouth, as 

 long as the eye; can thus rostralis indistinct; loreal region oblique, 

 concave; nostril nearer the eye than the tip of the snout; distance 

 between the nostrils greater than the interorbital width, which is 

 less than that of the upper eyelid ; tympanum very distinct, f to once 

 the diameter of the eye and close to it. 



Fingers moderate, obtusely pointed, first a little longer than the 

 second, third longer than the snout; subarticular tubercles moder- 

 ately large, prominent. 



Hind limb moderately long or rather short, the tibio-tarsal articu- 

 lation reaching the tympanum or the eye; heels meeting or over- 

 lapping when the limbs are folded at right angles to the body; tibia 

 3 to 3| times as long as broad, 2i to 2-j times jn length from snout to 

 vent, a little shorter than the fore limb or than the foot. Toes obtuse, 

 f webbed, 2 phalanges of fourth free; outer metatarsals separated 

 nearly to the base; subarticular tubercles moderate; tarsal fojd absent 

 or merely indicated; inner metatarsal tubercle oval, feebly prominent, 

 ^ the length of the inner toe; no outer tubercle. 



Skin smooth or with small warts above; a narrow, moderately 

 prominent glandular dorso-lateral fold, from above the tympanum 

 to beyond the sacral region, but not reaching the tip, the distance 

 between the folds 4 to 4| times in the length from snout to vent. 



Pale greenish above, with oval or round dark spots, which may be 

 light-edged ; spots on the limbs not forming regular cross-bars. Lower 

 parts white, sometimes profusely sprinkled with brown. Male with- 

 out external vocal sacs. 



Nasal bones large, in contact with each other and with the fronto- 

 parietalis, the ethmoid nearly entirely covered. 



