Three species of terrestrial slugs (Gastropoda) are native to Northeastern United States and Southeastern Canada. At least twelve additional species have been accidentally introduced from Europe. Many of the introduced species are now widespread throughout the region; some are commonly found in natural forested habitats. Because of the complexity of the systematics of some of the introduced species, dissection of internal anatomical structures and DNA and other biochemical analyses may be required to distinguish cryptic species. Although this key to the terrestrial slugs of the Northeastern United States and Southeastern Canada was developed in 1973, it remains the best tool in identifying the terrestrial slug species of the region. Because it was published in a relatively obscure journal that is not readily available, we are placing it on this web site where it can be readily accessed.published or submitted for publicationis peer reviewe
