We have applied the eyeball concept to Sun Dog's marble pattern. The three major elements of the eyeball are the Dorsal Eyelid, the Eyeball, and the Ventral Eyelid. Where the eyelids meet toward the head is called the Cranial Vertex. Where the eyelids would have met toward the tail is called the Caudal Vertex. In this case, the Eyeball is sufficiently distorted that no Caudal Vertex exists.
There are additional marble elements that are not derived from the bulls-eye, but are part of the marble tabby pattern. Two of these elements are the spinal lines and the butterfly.
The butterfly is the pattern between and on the shoulders. It divides the head lines from the spine lines. The spine lines are the wide, distinct stripes of the darker marking color divided by stripes of the paler ground color and they run from the butterfly to the tail.
