House of the Vettii, Pompeii.
In the center, the family Genius, in the form of a youth, offers a libation between two dancing Lares (gods of the hearth). Below, the same family Genius, this time in the form of a serpent, approaches a small altar. The altar bears food offerings which are not clearly visible in this photograph. The Genius was the spirit of the family and represented the continuity of the family's lineage through time.