_Proximal._–That end of any part or member which is nearest to the imaginary centre or axis of the body. _Racquet-shaped._–Used of feathers with bare shafts and roundish terminal vanes. _Rectrices_ and _Remiges_.–See _Coverts_, _Primaries_ and _Secondaries_. The _Rectrices_ usually number twelve, but vary from four to twenty-eight. _Reticulated_ (p. 10). _Rictal._–Belonging to the gape. _Roofed._–See _Vaulted_. _Sagittate._–Used of the tongue, and meaning arrow-shaped. _Scapulars._–The feathers lying along the _scapulae_ or shoulder-blades. _Scutellated_ (p. 10). _Secondaries_ or _Cubitals_.–Those wing-quills (_Remiges_) borne by the _Ulna_, which often exhibit roughnesses where they grow. They should properly be counted inwards from the wrist, and vary from six to thirty or more. _Spatulate._–Spoon-shaped. Used of the bill or of racquet-shaped feathers. _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. _Ventral._–The lower side of the body, in which lie the heart, lungs and digestive organs; and hence applied to the corresponding surface of any part or parts of the structure. _Zygodactylous_ (p. 10). {23}CHAPTER II ARCHAEORNITHES–NEORNITHES RATITAE–NEORNITHES ODONTOLCAE. The Class AVES is divided by Dr. Gadow (Bronn's _Klassen und Ordnungen des Thier-Reichs, Aves, Systemat. Theil_, p. 299) into two Sub-classes of like value, _ARCHAEORNITHES_ and _NEORNITHES_, though some writers prefer to consider the former as of equal rank only to the several subdivisions of the latter here adopted, namely, RATITAE, ODONTOLCAE, and CARINATAE (p. 25). The question is clearly one of degree, and depends entirely on the amount of weight assigned to the various points of distinction to be mentioned below.