Field studies on hylid frogs in southern México and northern Central America have resulted in the collection of numerous specimens of _Ptychohyla_, a genus of hylid frogs heretofore poorly represented in museum collections. Experience with the living frogs in their natural habitats has been helpful in defining the species and in formulating ideas concerning their […]

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 […]

In 1954, two of us (Jones and Byers) collected reptiles and amphibians in Korea incidental to field studies relating to hemorrhagic fever. The 382 specimens thus obtained were deposited either in the Museum of Natural History of The University of Kansas (KU), or in the Museum of Zoology of the University of Michigan (UMMZ), and […]

Preparation of a handbook of reptiles and amphibians by the junior author has led to a survey of the collections of these animals at Kansas State Teachers College in Emporia. Numerous locality records of interest and importance have been accumulated there through the efforts of the senior author and a number of his students, particularly […]

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 […]

In trying to determine the ancestral relationships of modern orders of Amphibia it is not possible to select satisfactory structural ancestors among a wealth of fossils, since very few of the known fossils could even be considered possible, and scarcely any are satisfactory, for such a selection. The nearest approach thus far to a solution […]

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 […]

Early in 1960 an unusual opportunity arose to carry on biological field work in the midst of virgin rainforest in southern El Petén, Guatemala. At that time the Ohio Oil Company of Guatemala had an air strip and camp at Chinajá, from which place the company was constructing a road northward through the forest. In […]

Information about osteological changes in the groups of reptiles that gave rise to mammals is preserved in the fossil record, but the musculature of these reptiles has been lost forever. Nevertheless, a reasonably accurate picture of the morphology and the spatial relationships of the muscles of many of these extinct vertebrates can be inferred by […]

In 1931 and 1932, H. H. Lane, C. W. Hibbard and W. K. McNown collected the specimens that Hibbard (1933) described and made the basis of two new species. These were from the Rock Lake shale member of the Stanton formation, six miles northwest of Garnett, Anderson County, Kansas. In 1954, from a locality (KAn-1/D, […]