Editing Catacombs of Rome (section)

==Typology==
Roman catacombs are made up of underground passages (''ambulacra''), in the walls of which horizontal niches (''loculi'') were dug. These loculi, generally laid out in sequences (''pilae'') one above the other from floor or waist level, could each contain one or more bodies. When placed inside of loculi, bodies were usually covered in a shroud and often covered in lime, which helped to cover the smell of the decaying process. In order to make more money, fossors would often sell occupied loculi to other people. A loculus large enough to contain two bodies were referred to as a ''[[bisomus]]''. Another type of burial, typical of Roman catacombs, was the ''arcosolium'', consisting of a curved niche, enclosed under a carved horizontal marble slab. ''Cubicula'' (burial rooms containing loculi all for one family) and ''cryptae'' (chapels decorated with frescoes) are also commonly found in catacomb passages. When space began to run out, other graves were also dug in the floor of the corridors—these graves are called ''formae''.