Speculum.–Strictly applied to a band across the wing, more or less metallic in colour, which occurs in the Duck-tribe.
Square.–Used of the tail when level at the end.
Syrinx (p. [13]).
Tectrices.–See Coverts.
Tertials.–A mistaken word for the inner secondaries.
Thighs.–Loosely used in describing plumage to indicate the feathers falling over the leg.
Trachea (p. [13]).
Tracheal syrinx.–One in which the lower portion of the trachea consists of thin membranaceous walls, about six of the rings being thin or deficient. Both inner and outer tympaniform membranes exist in the bronchi, as well as some vibratory tracheal membranes. The few muscles, generally but one pair, are wholly lateral.
Tracheo-bronchial syrinx (the normal form).–One which has this essential feature, that the proximal end of the inner tympaniform membrane, forming the median wall of each bronchial tube, is attached to the last pair of tracheal rings.
Vaulted or Roofed.–Used of the tail when compressed like that of a Fowl.