contour feather

Large rigid feather of the wings and tail enabling flight.

inferior umbilicus

Opening of the shaft located at the lower portion of the calamus; it is implanted in the skin.

superior umbilicus

Opening of the shaft located at the juncture of the calamus and the rachis.

barb

Each of the self-adhering filaments implanted on each side of the rachis.

rachis

Solid corneous upper portion of the shaft of the contour feather; it is an extension of the calamus and the barbs are attached to it.

calamus

Hollow corneous anterior portion of the shaft of the contour feather extending through the rachis.

afterfeather

Small soft light feathers usually located at the base of the main feathers on the abdomen; they help to insulate the body.

vane

All the interconnected barbs on the same side of the rachis forming a waterproof surface.