An index to the mammoth Sylloge Fungorum with the exception of Volume XIII. The Sylloge was Saccardo's attempt to list the names and provide a description of the fungi and bacteria known in the late 19th and early 20th centuries, and remains the only comprehensive listing of fungal taxa, covering some 28,000 pages in twenty six volumes. This index, as well as being the only direct access to the taxa covered, also explains many errors in the work, including the pagination problems in the original and Edwards reprints.