Cratenemertes variabilis and Amphiporus arenarius are transferred to the genus Hipponnemertes. Collarenemertes gen. n. is established for Amphiporus bimaculatus, distinct by bifurcal channels of the cerebral organs and skin collar forming at head drawing in. The family Cratenemertidae is insigned to Monostylifera. The class Enopla is divided into 3 orders: Monostylifera Brinkmann, 1917, stat. n., Polystylifera Brinkmann, 1917, stat. n., and Bdellonemertini Verrill, 1892.