The tadpoles of this species described by Duellman (1961:47) are like those of _Hyla robertsorum_ in having 2/3 tooth-rows, peglike serrations on the beaks, and long, rounded tails. At Uruapan tadpoles were found in a rocky stream on April 24, 1956, and metamorphosing young were found there on August 2, 1956. A completely metamorphosed juvenile has a snout-vent length of 24.8 mm.
_Hyla bistincta_ is found only along streams, where individuals can be seen clinging to vines and other vegetation closely over-hanging fast-moving parts of the stream.
_Distribution._--_Hyla bistincta_ occurs at elevations from 1400 to 2600 meters in the mountains of the Sierra Madre Occidental in western Jalisco southward through the Cordillera Volcánica in Michoacán, México, and Morelos, the Sierra de Coalcomán in Michoacán, and the Sierra Madre del Sur in Guerrero and Oaxaca, and thence northward in the Sierra Madre Oriental to central Veracruz (Fig. 2).
Specimens examined.--GUERRERO: Omiltemi, UIMNH 38023-5. JALISCO: 25 km. SE Autlán, UMMZ 102076. MEXICO: 19 km. W Villa Victoria, UIMNH 28162, USNM 114513. MORELOS: Cuernavaca, USNM 121523; _3 km. N Cuernavaca_, UIMNH 28168-70. MICHOACAN: Cerro San Andrés, UMMZ 102075; Dos Aguas, UMMZ 119193; _12.5 km. ENE Dos Aguas_, UMMZ 119194; _Los Conejos_, UMMZ 94238-40; Uruapan, KU 68077-8, 69093 (skeleton), UIMNH 20457, 28167, UMMZ 85452-3, 112838, 112839 (16), 115231 (tadpoles), 115232, 115233 (12), 121515, S-1699 (skeleton), S-1826 (skeleton), USNM 114514-5, 114517-24. OAXACA: Cerro San Felipe, UIMNH 28163; Pluma Hidalgo, AMNH 13447; San Lucas Camotlán, USNM 123689; San Vincente, UIMNH 51346 (Smith and Williams, 1963:23). VERACRUZ: no specific locality, USNM 32261; Cumbres de Acultzingo, CNHM 105482-3, UIMNH 28164-6, 49133-4, USNM 114525.
[Illustration: FIG. 2. Map showing locality records for _Hyla bistincta_ and _Hyla charadricola_.]
_Holotype._--University of Kansas Museum of Natural History No. 58414 from the Río Totolapa, 14.4 kilometers by road west of Huachinango, Puebla, México, 2280 meters; obtained by John Wellman on June 8, 1960.
_Paratypes._--KU 58415-58423, same data as holotype, and UIMNH 50966, obtained at the type locality by William E. Duellman on February 11, 1961.