Reflecting the growth in research on aquatic environments and organisms since 1950, this revised edition treats 71 species of Florida mayflies. The Florida fauna is compared with that of more northern regions, and habitats in which the nymphal stage occurs are described. Illustrated keys assist the user in identifying both adult and immature stages. The annotated list of Florida species contains references, discussion of taxonomy, geographic distribution, ecology, seasonal distribution, life history and behavior. Maps show the distribution of each form in Florida and many of the immature and adult stages are illustrated by 175 drawings.