Examination of populations of M. schencki Viereck at sites in Italy showed that there appeared to be an Italian form characterised by workers having much wider frons than is normal for M. schencki. Morphometric comparison with M. schencki from all over its range showed that not only do the Italian female castes have a wider frons, their males also have a relatively longer scape that is less acutely angled at its base. These differences are consistently sufficient for the Italian form to be a species distinct from M. schencki. Comparison with other forms in the schencki-species group of Myrmica Latr. shows its workers, queens and males to be fully compatible with the type specimens of M. schencki var. obscura Finzi, which was considered as a junior synonym of M. schencki. Here we revive the name M. obscura from synonymy and raise it to species. Its distribution is discussed.