I am, in truth, GREATLY obliged to you for your long, most interesting, and clear letter, and the Report. I will consider your arguments, which are of the greatest weight, but I confess I cannot yet bring myself to reject very WELL-KNOWN names, not in ONE country, but over the world, for obscure ones,--simply on the ground that I do not believe I should be followed. Pray believe that I should break the law of priority only in rare cases; will you read the enclosed (and return it), and tell me whether it does not stagger you? (N.B. I PROMISE that I will not give you any more trouble.) I want simple answers, and not for you to waste your time in reasons; I am curious for your answer in regard to Balanus. I put the case of Otion, etc., to W. Thompson, who is fierce for the law of priority, and he gave it up in such well-known names. I am in a perfect maze of doubt on nomenclature. In not one large genus of Cirripedia has ANY ONE species been correctly defined; it is pure guesswork (being guided by range and commonness and habits) to recognise any species: thus I can make out, from plates or descriptions, hardly any of the British sessile cirripedes. I cannot bear to give new names to all the species, and yet I shall perhaps do wrong to attach old names by little better than guess; I cannot at present tell the least which of two species all writers have meant by the common Anatifera laevis; I have, therefore, given that name to the one which is rather the commonest. Literally, not one species is properly defined; not one naturalist has ever taken the trouble to open the shell of any species to describe it scientifically, and yet all the genera have half-a-dozen synonyms. For ARGUMENT'S sake, suppose I do my work thoroughly well, any one who happens to have the original specimens named, I will say by Chenu, who has figured and named hundreds of species, will be able to upset all my names according to the law of priority (for he may maintain his descriptions are sufficient), do you think it advantageous to science that this should be done: I think not, and that convenience and high merit (here put as mere argument) had better come into some play. The subject is heart-breaking.