Passage between tombs 33 and 34

Originally there was a street between tomb 33 and tomb 34, which made the tombs behind accessible from the Via Severiana. Later on this passageway was closed with walls
on the east and west side.
The passage between the front of tomb 31 and the back side of tomb 33 was also closed (the wall with the attached floor-mosaic).
In this now closed area was a staircase to an upper floor and a furnace. It is not clear whether the staircase led to the second floor of tomb 31 or tomb 33.