[Illustration: FIG. 7. Map showing locality records for the species and subspecies of _Ptychohyla_.] The frogs of the _Ptychohyla schmidtorum_ group have more restricted geographic ranges than members of the former group. _Ptychohyla schmidtorum schmidtorum_ occurs on the Pacific slopes of the Sierra Madre in Chiapas and Guatemala, where it occurs with _P. euthysanota euthysanota_; _P. schmidtorum chamulae_ is known from only two localities on the Atlantic slopes of the Central Highlands of Chiapas, where it occurs close to, but as now known not with, _P. euthysanota macrotympanum_. On the Atlantic slopes of the Sierra Madre Oriental in northern Oaxaca _P. ignicolor_ occurs with _P. leonhardschultzei_. In the Sierra de los Tuxtlas in southern Veracruz and in the cloud forests along the eastern slopes of the Sierra Madre Oriental northward to Nuevo Leon, _Hyla miotympanum_ seems to be the ecological replacement of _Ptychohyla_. On the Pacific slopes north of Guerrero, Mexico, humid forests in which there are cascading mountain streams are absent; consequently, no _Ptychohyla_ are known from that region. In the mountains of El Salvador _Ptychohyla euthysanota euthysanota_ occurs sympatrically with another small stream-breeding hylid, _Hyla salvadorensis_. To the south of Honduras the highlands diminish into the lowlands of Nicaragua, where habitat suitable for _Ptychohyla_ apparently does not exist. In the mountains of Costa Rica and Panama, the habitats occupied by _Ptychohyla_ in northern Central America are filled by a variety of stream-breeding _Hyla_, such as _Hyla legleri_, _H. rivularis_, _H. rufioculis_, _H. alleei_, and _H. uranochroa_. Although members of the genus _Ptychohyla_ occur in the southern part of the Mexican Highlands to the west of the Isthmus of Tehuantepec, the greater distribution and differentiation in the genus is in the Chiapan-Guatemalan Highlands. In this respect _Ptychohyla_ is a counterpart of _Plectrohyla_. Habitat Preference