Notes on Bythinella, etc.

Last year I reviewed in the proceedings of this Society the synonomy of the genus Bythinella as far as it is represented by the small freshwater shells of our streams. Since then I have had my attention drawn by Prof. Tate to a species described by Messrs. Quoy and Gaimard, which from the figures and diagnosis I make no doubt belong to the genus, and probably a subsequently described species; have also had an opportunity of seeing Mr. J. Brazier's type specimens of his Amnicola petterdiana, in which I can see no differences to distinguish it from the shell already described. I was not able to examine this type specimen before, as Mr. Brazier had left Sydney, and his collection was packed away. In consequence of this I was obliged to omit any reference to the species in my last paper.