A revised census of the Tasmanian fluviatile mollusca

On entering on a revision of the Tasmanian freshwater molluscs, the question naturally arises why should this be necessary, seeing the great amount of attention given to this subject by a number of distinguished naturalists. The truth is that much overlapping has occurred in previous work, creating many synonyms, partly through ignorance, or uncertainty as to what previously described species really were, as they were usually not figured. Again, too much stress was laid on small variation in the erection of species, which variation proved to be individual, and not specific.