_Spinnerets._ Organs observed in various parts of the body, producing the waxy, cottony, or mealy matter. They consist of cylindrical internal tubes, sometimes ending on the skin, sometimes protruding outside it in the form of tubes, spines, or conical hairs. In the former case the orifices show them to be in some instances simple, and in others compound tubes.[B] In the _Diaspidinæ_, besides being scattered over the body, the spinnerets are arranged in groups on the last abdominal segment, and these groups afford excellent characters for specific distinctions. (Plate i., Fig. 4, for types of various spinnerets; Plate iii., groups of spinnerets of _Diaspidinæ_.) [B] Minute anatomical details are unsuitable for this work. The student may consult Targioni-Tozzetti, "Studie sulle Cocciniglie," cap. ii., p. 26. _Spiracles._ "Breathing organs:" the orifices in the body of the tracheæ or tubes conveying air to the blood. In the _Lecanidinæ_ they are usually four; simple circles, near the edge of the body, and with a few strong spiny hairs near them. In the _Coccidinæ_ they are often numerous. (Plate ii., Fig. 4; Plate xx., _n_.) _Spiracular spines._ Spiny hairs, usually three in number, of which one is rather long, close to the spiracles, in the _Lecanidinæ_. _Stigma_, _stigmatic spines_. Terms sometimes employed for spiracles, &c. _Tarsus._ The fourth joint of the feet, between the tibia and the claw. Its consisting of one joint (monomerous) is a distinctive character of the whole family. (Plate i., Fig. 6, _ta_.; Fig. 7, _ta_.) _Test._ The waxy, glassy, or horny covering produced through the spinnerets and concealing the insect in many _Lecanidinæ_ and some _Coccidinæ_. In this work it is not applied to the "scale" of _Diaspidinæ_ or to cottony secretions. _Thoracic band._ An appearance seen on the thoracic region in the male, looking like a broad transverse ribbon. _Thoracic region_, _thorax_. That part of the female or the male which bears the three pairs of feet, when the feet are present; or, if the feet are absent, the middle portion of the body, segmented or not. _Tibia._ The third joint of the feet, next the femur. (Plate i., Fig. 6, _ti_.; Fig. 7, _ti_.) _Tracheæ._ Tubes ramifying throughout the body, conveying air to the blood. Their orifices are the spiracles. The tracheæ, as in other insects, appear as if constructed of a network of fine spiral wires. (Plate ii., Fig. 4 _d_; Plate xx., _n_.) _Trochanter._ A small articulation, not a distinct joint (something like a knee-cap) of the feet, between the coxa and the femur. (Plate i., Fig. 6, _tr_.; Fig. 7, _tr_.) _Trimerous._ Three-jointed.