Hairy-faced "white-lipped" marmosets, or tamarins, of the S. nigrlcollis group are defined. The 3 spp. of the group, namely, S. graellsi, S. nigricollis and S.fuscicollis, are arranged by their key characters. The first 2 spp. are monotypic while S. fuacicollis comprises 13 races including the following described as new: S. f. avilagiresi, S. f cruzlima, S. f. crandalli. Bare-faced tamarins of thegenusSaguinus are represented by the S. oedipus group with S. leucopus, S. oedipus (geoffroyi a spp.), S. inustus, and by the S. bicolor group. The latter is monotypic with sspp bicolor, martinsand the intermediate ochraceus described as new.