Duke seal

What is the image of the seal used on a Duke flag located on top of McClendon Tower and in front of Richard White Lecture Hall? It seems the text is all in Latin and this image is not commonly used as an insignia for Duke.

It’s the Duke “seal,” which isn’t used much anymore compared to the official “shield.” Details can be found on the University Archives web site: http://library.duke.edu/uarchives/history/histnotes/insignia.html