International Catacomb Society Image Archive

Available

 * (behind paywall): http://www.catacombsociety.org/ics-image-archive/

Description
(from website, consulted 2015-10-07)
 * The archive of the International Catacomb Society contains approximately 5,000 photographic images, which are completely digitized and cataloged in a searchable database. The strengths of the archive include the Jewish catacombs of Rome, epigraphy from the catacombs, and early Christian and Jewish iconography.