[From introduction:]
When, in the summer of 1878, Sir Wyville Thomson wrote me, inquiring if I knew of any branched annelid, I believe that the substance of the knowledge then extant was expressed when I mentioned that, though familiar with budding in such Turbellarians as
Catenula, with the propagation by division in
Nais proboscidea and
Chaetogaster, as well as the more complex condition in
Autolytus,
Myrianida, and
Filigrana, I could not say that I had seen or read of a well-marked case of the kind. The subsequent arrival of a Hexactinellid sponge containing the annelids, and the various slides with mounted specimens, placed all doubts at rest; and, at Prof. Sir Wyville Thomson's request, I now make a note on this remarkable form. Unfortunately, the annelid was not observed till the return of the Expedition, and after immersion in spirit.