Thorough, organized guide to North America's venomous lizards, elapids, and vipers. Dr. Ernst provides, for each individual species, a detailed description & confusing species, karyotype, fossil record, distribution/range map, habitat information, typical behavior (including reproduction & feeding), predators/defense, and geographic variations. Additionally, he provides detailed information on each species' venom (toxicity, symptoms, antivenin information). At least one high-quality color photo for each species as well as several black & white prints. Overall, the book is technical enough for more advanced readers while still coherent to those less versed in the content area.