Oni Figure from Ife-Ife
Ife (Metropolitan Museum)
Another example at the British Museum
Another one at the Brooklyn Museum
ALSO: don't neglect the side material in your book: read the three boxes on "Dating African Art and Identifying African Artists" (p. 187); the one on p. 189 about "Art and Leadership in Africa" and (very important) the one on "Idealized Naturalism at Ife-Ife" on page 190.