Endemics and immigrants: North American terrestrial isopods (Isopoda, Oniscidea) north of Mexico

Terrestrial isopod species recorded from Canada and the continental United States are listed with the original literature citation for each province a nd state record. The major habitat preference of each species is given. Mar ine littoral and cave dwelling species are generally endemics and the major ity of isopods from other habitat types are assumed immigrants. Distributio n and habitat data are analysed fur implications regarding the origins of v arious elements of the North American fauna and conservation concerns.