Members of the aquatic dance fly genus, Clinocera, are significant predators in temperate freshwater lotic habitats. Some 14 000 museum specimens were examined in detail to produce this book, which is dedicated to the classification, taxonomy, distribution and zoogeographic history of 67 New World species of Clinocera, including the description of 49 new species. Identification keys to genera of the subfamily Clinocerinae of North and South America are included and keys are provided to species groups and all known New World species of Clinocera. Descriptions are accompanied by 5 colour plates, 83 line drawings, 11 scanning electron photographs, 44 wing photos and 34 distribution maps.