The small yellow tree frogs, _Hyla microcephala_ and its relatives, are among the most frequently heard and commonly collected frogs in the lowlands of southern México and Central America. The similarities in size, proportions, and coloration of the different species have resulted not so much in a multiplicity of specific names, but in differences of […]

According to the most recent review of the Mexican amphibian fauna (Smith and Taylor, 1948), six genera of leptodactylid frogs occur in México. One other genus, _Pleurodema_, occurs in Lower Central America. Smith and Taylor recognized one species of _Engystomops_, 28 of _Eleutherodactylus_, three of _Leptodactylus_, eight of _Microbatrachylus_, 12 of _Syrrhophus_, and five of […]

Biological exploration of México and Central America has revealed the presence of a diverse fauna, elements of which have undergone speciation in separate areas within the relatively small region. Some genera of amphibians, especially _Eleutherodactylus_ and _Hyla_, are represented by many species having small geographic ranges in México and Central America. Most of the species […]

Few regions in Middle America are so important zoogeographically as is the Isthmus of Tehuantepec, that neck of land connecting North America with Central America, separating the Pacific Ocean from the Gulf of Mexico by a distance of only about 220 kilometers (airline), and forming a low break between the highlands of México and those […]

For almost 30 years North American herpetologists have been making extensive collections of reptiles and amphibians in México. Some parts of the country, because of their accessibility, soon became relatively well known; other regions lying off the beaten path were bypassed or inadequately sampled. Principally in the last decade herpetologists have been entering regions from […]