a EXPLANATION OF TERMS. 
for specific distinctions. (Plate i., Fig. 4, for types of various spinnerets ; 
Plate iii., groups of spinnerets of Diaspidine.) 
Spiracles. ‘Breathing organs:” the orifices in the body of the trachee or 
tubes conveying air to the blood. In the Lecanidine they are usually four ; 
simple circles, near the edge of the body, and with a few strong spiny hairs 
near them. In the Coccidine they are often numerous. (Plate ii., Fig. 4; 
Plate xx., 7.) 
Spiracular spines. Spiny hairs, usually three in number, of which one is rather 
long, close to the spiracles, in the Lecanidine. 
Stigma, stigmatic spines. Terms sometimes employed for spiracles, &c. 
Tarsus. The fourth joint of the feet, between the tibia and the claw. Its con- 
sisting 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 Lecaidine and some Cocciding. In 
this work it is not applied to the “scale” of Diaspidine ox to cottony secre- 
tions. 
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, ¢i.; Fig. 
7, tt.) 
Trachee. Tubes ramifying throughout the body, conveying air to the blood 
Their orifices are the spiracles. The trachez, as in other insects, appear as 
if constructed of a network of fine spiral wires. (Plate ii., Fig.4d; Plate 
XX., 71.) 
Trochanter. Asmall articulation, not a distinct joint (something like a knee-cap) 
of the feet, between the coxa and the femur. (Plate i., Fig. 6, t7.; Fig. 
Thy ea) 
Trimerous. Three-jointed. 
Ventral. On the under-side, the insect being in its proper position. 
