In almost every volume of the Corpus Inscriptionum Latinarum, revisions or supplements interfere with the systematization of the Latin inscriptions. New editions, corrections, annotations, and addenda pertaining to previously published inscriptions make it difficult to keep track. They are, however, the necessary consequence of the growth in the collection of inscriptions from the Roman Empire, a body of material constantly in need of updating. The 150th anniversary of the Corpus Inscriptionum Latinarum is being marked by the publication of the Index numerorum, which provides the entire corpus with a catalogue of all inscription references that are scattered in diverse publications. The Index is an invaluable resource for the epigrapher wishing to maintain a grasp of nearly 200,000 inscriptions. It also contains cross-references to the publication of inscriptions in the Ephemeris epigraphica, B cheler's Carmina Latina epigraphica, Dessau's Inscriptiones Latinae selectae, H bner's Exempla scripturae epigraphicae, the Greek inscriptions documented in Corpus Inscriptionum Graecarum and Inscriptiones Graeca, and the Inscriptiones Christianae urbis Romae.