Insular iconography Style II
As discussed by Carola Hicks, style II represents animals drawn in their completion in a "stressed linear form" which is ribbon-like and forms an interlace pattern (11-12). The Celtic design students identified the first night of class in the Amiantus manuscript is formed by these interlace patterns. In the discussion of art in the eighth and ninth centuries, Carola distinguishes between "Style II" and "plastic" styles to distinguish between consistently linear (stiff) interlacing and more fluid animal lines, which may vary in their line length, curvature and depth.
Hicks, Carola. "The Sixth Century." Animals in Early Medieval Art. Edinburgh:Edinburgh University Press, 1993.