RESUMO
Of all the amycines, the acutidens group of species of Mago is one of the most commonly collected groups throughout the Amazon. Redescriptions of M. acutidens Simon and M. longidens Simon by Galiano initially helped separating the two species, but then it became clear that we were dealing with a group of several similar species demanding revision. In order to make identification possible, we present here a revision of this newly proposed group of species, providing illustrations of the male palp and epigyne for all the recognized species. The female of M. longidens Simon is described for the first time. Besides the new records for both M. acutidens and M. longidens, we present M. jurutiensis sp. nov. and M. similis sp. nov. from Juruti, Pará, Brazil, M. delicatus sp. nov. from several localities in the Brazilian states of Amazonas and Pará, and M. balbina sp. nov. from Presidente Figueiredo, Amazonas. Maps with collecting records for all species of the group are presented.