In the early spring of 1887, while arranging the National Museum collection of Arctiidœ, I tried to make out the varieties of Callomorphalecontei listed in our catalogues, and soon came to the conclusion that we had to do with more species than were generally accepted. I investigated the literature of the subject and prepared a paper, the results of which were first communicated to the Entomological Society of Washington at their March meeting (see Entom. Americ., iii., p.20).