About three years ago I commenced the study of the “featherwings,” with the intention of preparing at some future time a monograph of the North American species of this family. While adhering to my original intention, I have decided to so far modify it as to publish in advance certain new species which have accumulated on my hands, and I am induced to this course the more because it may be a considerable time before sufficient material will have been obtained to justify me in publishing my general paper.