A new genus Diphyonyx is proposed here for a previously unrecognised lineage of geophilid centipedes. It is distinct from other geophilids in its unique combination of morphological characters, including the peculiar shape of the pretarsus of the legs on the anterior part of the trunk. The type species D. conjungens (Verhoeff, 1898), comb. n., is redescribed in detail and its geographical distribution updated (Balkan Peninsula, Anatolia, Crimea). Included in Diphyonyx are also D. sukacevi (Folkmanová, 1956), comb. n., and D. garutti (Folkmanová & Dobroruka, 1960), comb. n., both from southern Russia. D. garutti is raised here to species rank.