"The Erithraean Sibyl," placed beneath the narrative of "The Sacrifice of Noah," reiterates the fact she was Noah's daughter-in-law; it was she who foresaw the coming of Judgment Day. As well as symbolizing the link between the ancient Classical and Christian worlds, the sibyls also function as representatives of the ancient civilizations from which they came: Erithraea represents Ionia, Delphica Greece, Persica the Persian Empire, Cumaea Rome, and Libya the continement of Africa.
Erithraea sits with her legs crossed and her face towards that of the neighboring prophet, Ezekiel. With one muscular arm, she reaches forward to turn the pages of her book, while the other is relaxed by her side. This posture leaves the upper half of her body in an open, frontal position in contrast with the twisted, closed lower half of her body.
Above her books are two genii, one hidden in shadow. These genii appear in pairs next to all of the prophets to the neo-platonic philosophy that every person is born with two such spirits that reflect the dual nature of their spiritual and material sides. The genii blow upon the flames of a torch to enable the sibyle to read her book.