Preparatory to a revision of the Nearctic Hemerobiidæ I present descriptions of a few new species of Hemerobius. A few of the names have been used already elsewhere, but without description. Outline figures of the male genitalia will be given in the forthcoming revision.Hemerobius transversus, n. sp.—Face shining black, vertex and antennæ pale yellowish; thorax pale, a black stripe across front part of the mesothorax; abdomen brownish; legs pale yellowish. Wings with the margins faintly but broadly clouded with brown; the gradate series marked with dark brown, and a brown band between the first and second first.