This paper is intended to bring up to date our knowledge of the Nsorth American species of Aradus, and it is supplementary to my Essay on this group published in 1921. (Trans. American Ent. Soc., XLVII: 1-106, pls. I-VII.) It is based largely on Canadian material sent to me by Dr. J. McDunnough, William J. Gerhard, and W. Downes. Although collectors have shown a considerable interest in the genus, very few new species have come to light; and so it seems likely that our knowledge in this direction is nearly complete. However, those who have access to collecting grounds which are comparatively unmarked by civilization may still discover new forms; and their activities are the more to be urged, since these insects are undoubtedly becoming extinct, as forests disappear and suitable habitats are more and more restricted.

Several years ago Mr. H. C. Fall asked to see our Podabrus. A number were returned with MSS. names upon them, but Mr. Fall did not seem anxious to publish at that time and in fact did not publish until a year or two later.

No mention is made in the preface of having studied our material, although later under the several species are many references to specimens and localities in our collection.

Of the five species of Homaemus recorded from America, north of Mexico, proteus Stal. and parvulus (Germ.) are cnnfined tn the southern half of United States; variegatus Van D. is known only from California; bijugis Uhl. ranges throughout middle and western United States and Canada, extending southward to Colorado, New Mexico and California; aeneifrons (Say) has been commonly recorded from the Atlantic to the Pacific in northern United States and Canada and has been reported from the southwest from Colorado, New Mexico and California.

The following short list with the accompanying notes is based upon a collection of some 2100 species collected by myself during the past eighteen years. My original intention was to publish a list of Minnesota Coleoptera, but lack of time renders this project not likely of accomplishment.

While making a study of the aquatic fauna of Waddell Creek, Rancho del Oso, California, during the summer of 1928, the author collected, along with nymphs of several genera of Ephemerids, nymphs of Ephemerella hecuba Eaton figured by Eaton in his Revisional Monograph, page 133, Plate 40, figures 1-17, and by Needham in the Annals of the Entomological Society of America, volume 20, page 115, and in Bulletin 201, Utah Experiment Station, page 9. Inasmuch as the author was unable to find descriptions of the male and female imagoes in the literature he reared out adults, both male and female, in order to secure material for description. Subimagoes appeared July 11 and the imagoes issued July 12.