Lumbrineris cingulata (Ehlers, 1897) and Scolelepis mesnili (Bellan and Lagardere, 1971), new species for the Polychaete fauna of the Mediterranean Sea, are reported from the Alfagues inlet (Delta del Ebro, Western Mediterranean Sea). A brief diagnosis and iconography, as well as other ecological and bionomical informations, and present geographical distribution are reported.