All of the species described below were taken in Colorado. For most of the specimens I am indebted to the industry of my wife, who has done a large amount of work with the sweep net in Northern Colorado. No American species have yet been described as belonging to any of the genera mentioned, though some of the species described under Allotria may possibly be referable to some one of them. A number of species of Allotria in my collection are left until such time as the already described forms are more fully elucidated.