Five previously described species of the North American genus Eutyphlus LeConte, 1880 are redescribed. Eutyphlus spiralis Owens and Carlton, new species (type locality: Macon County, North Carolina), is described based on characters of the male genitalia. A key to species, drawings and photographs of diagnostic characters, and distribution maps are provided. Intraspecific variation of male secondary sexual characters of Eutyphlus prominens Casey and Eutyphlus dybasi Park are documented for the first time. A morphology-based cladistic analysis of Eutyphlus species, putative related genera within the tribe Trichonychini, and numerous outgroup taxa was performed to test the monophyly of Eutyphlus and evaluate placement within genus-group taxa of Euplectitae. The resulting phylogenetic hypothesis supports the monophyly of Eutyphlus, but highlights lack of resolution of genus-group taxa of the supertribe Euplectitae due to extensive homoplasy of characters used to diagnose taxa.