Paper published in 1910 in Memórias do Instituto Oswaldo Cruz, v.2, n.2, p.213-67, in Portuguese and German (two columns). Lutz was to publish two other special communications on Simuliidae in the Oswaldo Cruz Institute periodical in 1909 (v.1, n.2, p.124-46), likewise in Portuguese and German, and in 1917 (v.9, n.1, p.63-7), in Portuguese only. They have also been reprinted in this volume. Many notes handwritten by Lutz, along with draft versions of the aforementioned special communications with corrections by the author, are part of the Fundo Adolpho Lutz, held at Museu Nacional, in Rio de Janeiro (file Simuliidae). [E.N.]