A titular see in Mauretania Sitifensis, suffragan of Sitifis, or Sétif, in Algeria. It is not, as is sometimes stated, the Island of Lesbos, which never was a titular bishopric, and which, moreover, possesses, two titular archbishoprics: Mytilene and Methymna. Of Lesbi we only know, from the "Itinerarium Antonini", that it was situated twenty-five miles from Tupusuctu or Tiklat, and eighteen miles from Horrea Aninici, now Ain-Roua, south of Bougie. The town, therefore, was on the Sava, i.e. the Oued-Bou-Sellam, but there are no remains to be seen. Two of its bishops are recorded: Romanus, a Donatist, present at the convention of Carthage, 411; Vadius, a Catholic exiled by King Huneric, 484.
TOULETTE, Geographie de l'Afrique chretienne: Mauretanies (Montreuil, 1894), 212.