The article takes as its starting point a well-known article by Philip Hofer in 1932, which described the presence in a copy of the 1499 “Hypnerotomachia Poliphili” of five sheets produced with a different setting of type. Due to the fact that the said copy at the time belonged to a private collector, the explanation given by Hofer, that these sheets were “cancellanda”, or a first version of the text, later substituted, has not been challenged. The discovery of other copies containing such sheets, of which nine are now known, and the re-emergence of the copy described by Hofer in the library of Princeton University, allow a more precise bibliographical analysis. As is shown by damage to the woodcut illustrations, these sheets belong to a later setting, probably made shortly after the original printing, in order to make up for short-falls in the press-run. There follows a detailed description of the reprinted sheets and a list of the copies in which they have so far been found.
