http://www.log24.com/log/pix11B/110916-ArtJungToronto-NYT.jpg

Related art—

Midnight's Icons,

http://www.log24.com/log/pix11B/110915-Jung-FourDiamonds.gif

Faust in Toronto,

http://www.log24.com/log/pix11B/110916-NYT-Faust.jpg

and…

McLuhan 'tetrad' figure with four diamonds surrounding a fifth, the medium

McLuhan and the Four Diamonds

(Wikipedia figure)

"Visually, a tetrad can be depicted as
 four diamonds forming an X…."

" X never, ever, marks the spot."