Ten new species of Oligochaeta of the genera Glossoscolex (9) and Fimoscolex (1) are described from material collectedin northern Paraná and neighboring São Paulo State, Brazil: Glossoscolex lutocolus n. sp., G. palus n. sp., G. itaguajensisn. sp., G. uliginosus n. sp., G. primaensis n. sp., G. mariarum n. sp., G. sanpedroensis n. sp., G. giocondoi n. sp. andFimoscolex bartzi n. sp. The subgenus Glossoscolex (Praedrilus) is validated, with the inclusion of three more species (G.lutocolus n. sp., G. itaguajensis n. sp., and G. uliginosus n. sp.). The truncatus species group (male pores in xvii) ofGlossoscolex (Glossoscolex), to which the remaining six new Glossoscolex were assigned, is more problematic becauseseveral characters conflict with the character used to define this group (position of male pores). The relationships betweenGlossoscolex (Assudrilus) and Fimoscolex are discussed, and Fimoscolex sacii (Righi, 1971) is re-ascribed toGlossoscolex (Assudrilus). A new species of the genus Fimoscolex is presented, with a single intraclitellar male pore. Weprovide a table of characters in order to clarify the differences among the species described and the main species groupsand sub-genera of Glossoscolex, as well as some information on the ecology of some of the new species, including habitat and soil associations.