_Remarks._--_Rana rugosa_ was associated with _Rana nigromaculata_ and _Rana amurensis coreana_ at all localities where the species was taken save at 2 mi. E Hoengsong, where _R. a. coreana_ was not observed. Three specimens of _R. rugosa_ were collected among grasses and reeds in water along the edge of Ch´orwon Reservoir, 2 mi. S Ch´orwon, where they were difficult to find in the thick vegetation even though their low, soft calls were heard; the specimen from 1 mi. NW Oho-ri was found in a rice field. Otherwise, habitats recorded indicate a preference for small, fast-flowing streams, especially in wooded valleys. On one occasion, individuals were found trapped in cement-walled pits about old ruins on a wooded hillside in the Central National Forest. The earliest and latest dates of capture among our specimens are May 15 and November 6. In addition to the localities listed above, the species was observed 4 mi. W Ch´ungju. _R. rugosa_ may have an extensive breeding season as suggested by the variation in size of frogs collected or observed in 1954. Of nine frogs obtained on May 29, five ranged in snout-vent length from 26 to 28, and four from 42 to 54. Three specimens collected on October 9 measured 39, 41, and 55, and two obtained on November 6 measured 25 and 37. =Rana nigromaculata= Hallowell _Rana nigromaculata_ Hallowell, Proc. Acad. Nat. Sci. Philadelphia, [12]:500 (for 1860), 1861 (type locality, Simoda, Japan). _Specimens examined_ (47).--Central National Forest, near Pup´yong-ni, 6 (KU); 2 mi. S Ch´orwon, 5 (KU); 4 mi. W Ch´ungju, 2 (KU); 7 mi. W Ch´ungju, 1 (KU); 2 mi. E Hoengsong, 1 (KU); 8 mi. SW Kunsan, 1 (KU); 1 mi. NW Oho-ri, 5 (KU); 5 mi. ENE Pusan, 2 (KU); 5 mi. ESE Seoul, 9 (KU); 6 mi. E Seoul, 3 (KU), 10 (UMMZ); 6 mi. NNE Sogwi-ri, Cheju Do, 2 (KU). _Description._--Back brownish or grayish (greenish in life), having few, indistinct or well-defined, dark blotches, or extensive blackish areas (representing fusion of markings); pale, middorsal stripe (pale green, buff or yellowish in life) from snout to anus, sometimes as wide as interorbital width, but indistinct or lacking when pattern on back absent; blackish bar often present behind tympanum; posterior surface of thigh mottled; underparts pale yellow to whitish, sometimes having a few dusky marks on throat; longitudinal ridges between dorsolateral folds indistinct in some small frogs; largest female and male having respective snout-vent lengths of 100 and 70.