point c to e quite free.
it is at point a, starting from a little hole, that the sharp edge begins; and near this point the corner of the eye is situated: a, figs. 1, 2, 3.
from points a to f the bony edge of the opening is very near the surface and should be looked for.
the next thing to note is the fact that the eyebrow at first follows the upper edge of the bony opening from b to c, but that from point c it crosses the free arch between c and d and soon ends.
so that considering the under side of the eyebrow, whereas from point c towards 