These photos supplement pages 119-135 of the Guide to Aquatic Invertebrates of the Upper Midwest. Information on the biology of Phryganeidae can be found on page 134. Rhyacophilidae have a sclerotized pronotom, but a membranous meso and meta notum. The dorsum of segment 9 is sclerotized. The main identifying characters are the lack of prosternal horn and dorsal and lateral humps on abdominal segment 1 (compare with Phryganeidae) and the fact that their anal prolegs are free of abdominal segment 9 (compare with Glossosomatidae). Rhyacophilidae do not build cases.