Pseudexogone Augener, 1922, with P. backstromi Augener, 1922 as the type and only species, has been regarded as a member of the family Syllidae. It was questionably placed in the Syllidae in the description and apparently some morphological features were confused. The type material is lost. In this contribution: 1) Pseudexogone is redefined with the apparent autapomorphy of having curved, bidentate notospines; 2) Pseudexogone is transferred to the Pilargidae, closely allied to Synelmis Chamberlin, 1919; 3) those species described or identified as Synelmis dineti Katzmann, Laubier & Ramos, 1974 are regarded as members of Pseudexogone; and 4) additional species from several localities are described. Specimens were studied by using light and scanning electron microscopy. Besides the type species, four other species are distinguished by using the presence of eyes and type of furcated chaetae: P dineti n. comb., from the Mediterranean and northeastern Atlantic Ocean; P helmuti n. sp. from the southern Indian Ocean; P imajimai n. sp., from the western Pacific Ocean;, and P williamsae n. sp., from the eastern Pacific Ocean. A key is included to identify all species in the genus.
