Jesus with the Samaritan Woman by the Well
Mid-4th century
Lunette in an arcosolium, catacomb on the Via Latina
This episode from John 4:3-38 is relatively rare in the catacombs (from the end of the second century to the fourth). Jesus promises the Samaritan woman "living water" by which a person "shall become…a fountain of water, springing up into life everlasting." The kantharos that the woman holds is a traditional symbol of resurrection to eternal life. The palm branch lying on the right is also traditional, symbolizing the Christian's victory over sin and death.
Even the unusual shape of the well has symbolic value, for it echoes the shape of the urns in contemporary images of Jesus turning water into wine
(example).
That miracle was itself taken as a type of the Eucharist.
Read more about the kantharos and palm branch symbols.
Read about other images of Jesus and the Samaritan woman.
Source: The Christian Catacombs of Rome