Until now, no detailed treatment of the Pennsylvania herpetofauna has ever been published, nor have recent books dealt with the herpetofauna of the entire northeastern United States. Amphibians and Reptiles of Pennsylvania and the Northeast is a comprehensive guide to the amphibians and reptiles of the whole region. Each account contains a general description of the species, major color and pattern variations, ontogenetic changes in patterns and appearance, confusing species, range, and ecology and reproductive biology. This guide is intended for use by both amateurs and professionals and allows convenient retrieval of field data and natural history accounts. Amphibians and Reptiles of Pennsylvania and the Northeast:* Contains complete and easy-to-use keys to all the reptiles and both the adult and larval amphibians of the Northeast.* Features high-quality photographs to illustrate all species of amphibians and reptiles in the region as well as their significant color variations and life history stages.* Includes detailed spot-distribution maps of each species within Pennsylvania and outline maps of each species' distribution throughout the northeastern United States. * Presents extensive new data on the status and distribution of the amphibians and reptiles of Pennsylvania.