In December 1970 the British Museum acquired from the British School at Rome a small printed book, in quarto, undated and without title or imprint, and consisting of twelve leaves of text, with a number of woodcut ornamental borderpieces, and on the first three leaves two woodcut signs of the zodiac at the top of each page. The book is very rare, copies being known in the following libraries: Rome, Biblioteca Angelica; Vatican; Seville, Biblioteca Colombina; London, British Museum (formerly British School at Rome copy, acquired by Thomas Ashby from the Rome bookseller Silvio Bocca in 1924); Milan, private collection of C. E. Rava. Theodor Mommsen wrote in 1893 that another copy ‘nuper comparavit bibliotheca nostra regia’, i.e. the Preussische Staatsbibliothek: I have not ascertained whether this copy is still in Berlin. Sander describes the book as a Calendarium, and adds, without giving any reason, that it was printed before September, 1515. As will be seen later, it must have been printed before May, 1515. Rava, in his recent supplement to Sander, shows that as Sander had not seen a copy he makes a number of errors in his description. Rava rightly says that this little work ought to be described as ‘Calendarii et Fasti’, since it is not a calendar in the modern sense, but more precisely it reproduces the texts, partly fragmentary, of ancient calendars and Roman fasti engraved on slabs of marble, which the anonymous compiler had collected in various places.