Anatomical-histological examinations have made it possible to place with certainty 21 species of the “Peloscolex” complex, including Embolocephalus alaskensis sp.n., E. confusus sp.n. and Baikalodrilus digitatus sp.n., into the eight genera established in the first part of this revision. Owing to deficient and unsatisfactory material and to obscurity as regards related tubificid genera, the placing of ten of the studied species must continue to be regarded as uncertain, and that of four more species could only be suggested. Of the species not studied, most descriptions give no details of the important genital organs, or only inadequate ones. These species are undistinguishable. Only in a few cases has a suggestion been possible. |
