A transcription is given of a series of letters written in 1900 to H. M. Bernard (then working on theCatalogue of corals in the British Museum)by Ray Lankester, Sir W. Thiselton‐Dyer, W. F. R. Weldon, George Murray, William Bateson, David Sharp and Alfred Russell Wallace. The letters concern an unpublished (and lost) essay by Bernard on nomenclature and the species problem. Bernard's ideas were presented in a paper read to the Linnean Society in 1901. A commentary on the letters and their writers is adde