A collection of 54 articles from Italian newspapers and local Sienese monthlies, from October 1977 through July 1981, on the discoveries and debates generated by the conclusion of the American scholar Gordon Moran that on the basis of historical, documentary, topographic, and technical evidence the mural of Guidoriccio da Fogliano in the Sala del Mappamondo of the Palazzo pubblico in Siena traditionally attributed to Simone Martini does not represent Guidoriccio and was painted not by Simone Martini but probably at the end of the 15th century. The articles, some by Moran himself, set forth and discuss his evidence, and report on the discovery below the alleged Guidoriccio of another mural of the early 14th century depicting a commander who almost certainly is Guidoriccio standing next to one of the castles which he took for the Sienese. Circular marks on the surface of the mural suggest that a topographical map of the territory of Siena, also a work of the 14th century, had been installed on the same wall. While further studies of the evidence and additional probes for frescoes on the same wall that may have been painted over are being planned, the Sienese art-historical establishment continues its opposition to Moran's conclusion. Both his conclusion and his evidence are accepted,however, by Federigo Zeri. -- AATA