Amazon.com description: Product Description: Contains a comprehensive listing of 433 snake species, subspecies, intergrades, hybrids, & color phases found in the U.S. & Canada. Both native & introduced species have been included, illustrated by color photographs. The format of this lifelist is, with a few exceptions, in taxonomic order, which is the order utilized in most current field guides. Recording your observations of different species or forms on this lifelist will enable you to retain memories of a lifetime of herpetological field trips. Documenting the habitats, habits, size, sex, etc., of new forms will help you learn more about snakes in general.