The 196 species of Odonata known to occur in Canada are divided into two suborders: Zygoptera (52 species) and Anisoptera (144 species). None of these exclusively occupies marshes or fens. One zygopteran (Nehalennia gracilis Morse) is restricted to bogs whereas Coenagrion interrogatum (Hagen) predominantly occupies mossy bogs or fens. The following anisopterans solely, or predominantly, occupy bogs (with some occasionally in Carex marshes and (or) fens): Gomphaeschna furcillata (Say), Aeshna septentrionalis Burmeister, A. sitchensis Hagen, A. subarctica Walker, Williamsonia fletcheri Williamson, Somatochlora brevicincta Robert, S. franklini (Selys), S. incurvata Walker, S. sahlbergi Trybom, S. septentrionalis (Hagen), S. whitehousei Walker, Nannothemis bella (Uhler), and Leucorrhinia patricia Walker. Most of this information is based upon collections of adults, but studies of larvae are needed to determine the adaptations necessary for life in bog, fen, or marsh habitats.