Coverts (tectrices).–Feathers that cover the base of the quills (Remiges, oar-feathers) of the wing and of the tail (Rectrices, steering-feathers). The wing exhibits several series above and below (greater, median, and lesser). Unless otherwise specified, "coverts" in the text refer to upper coverts.

Cubitals.– See Secondaries.

Cuneate.–Wedge-shaped.

Decomposed (p. [3]).

Depressed.–See Compressed.

Distal.–That end of any part or member which is furthest from the imaginary centre or axis of the body.

Dorsal.–The upper side of the body; and hence applied to the corresponding surface of any part or parts of the structure.

Filoplumes.–Filamentous or hair-like feathers.

Flanks.–The portion of the sides near the leg.

Graduated.–Used of the tail when its feathers diminish in length gradually.