Figure 6.

Drawing of feather distribution pattern. Filoplumes are very small, difficult to see and located right along the rachis. Plumules are located between contour feathers. Nine plumules (numbered 1–9) are adjacent to each contour feather. Three of the plumules (1, 4 and 7) are shared with two other contour feathers (e.g. plumule 1 is shared by contour feathers A, B and C). The six other plumules (2–3, 5–6, 8–9) are shared by one other contour feather (e.g. plumule 2 is shared by feathers A and B and plumule 9 is shared by feathers A and C). In order to show the pattern, feathers are not drawn to scale. Illustration by C. N. Cruz.