From Celtic Art, the Methods of Construction by George Bain, 1951; Plate W pg. 126

Actual diameter in the Book of Kells is 1-1/3 inches! See it in context at sacred-texts.com. An exhaustive introduction to the Book of Kells is also available on that site.

Contains 4 beasts, 8 birds (2 with topknots), 4 reptiles with topknots and tails, 4 plants with leaves and fruits, Vegetation marks the commencement of decadence in Pictish Art. It may have entered by the Roman-British church. ...one exception: the plants are not in pots.

Scanned image is 3-3/4 inches. Colored by Comyn (color scheme does not match the original)