Epacanthion agubernaculus sp. nov. (Thoracostomopsidae, Nematoda) is described from sediments of Campos Basin,
Atlantic Southeast, Brazil. The main features are: the long spicules, the absence of gubernaculum, and the presence of three pairs of setae in the tail region.. Only one male was found for description, but the main features are strong enough to consider it clearly as a new species. An updated and modified key for species identification is proposed.