This is a revision, based primarily upon male genitalic characters, of the American species of Melanonemotelus, genus Nemotelus, north of Mexico. Previous to this paper 15 species from this region had been described. Nine new species are described, and all old species are redescribed. Five species are placed in synonymy. In addition, the range of the European species, Nemotelus nigrinus Fallen, is extended to this region, as four American species are placed in synonymy with it. New species described: Nemotelus politus, N. jamesi, N. variabilis, N. centralis, N. halophilus, N. sabroskyi, N. communis, N. picinus, N. tenuistylus. Species placed in synonymy: Nemotelus carneus Walker 1849 (syn. of N. nigrinus Fallen 1817), N. crassus Loew 1861 (syn. of N. nigrinus FAllen 1817), N. unicolor Loew 1861 (syn. of N. nigrinus Fallen 1817), N. carbonarius Loew 1865 (syn. of N. nigrinus Fallen 1817), N. fulvicornis James 1936 (syn. of N. glaber Loew 1872).