Diaspidinæ, are minute, flat, more or less rounded projections, two or more, seen on the edge of the abdominal extremity, usually interspersed with spines and hairs (Plate III, Figs. 1, 3, 4, 5, l); in the Lecanidinæ, are two triangular or conical projections, usually bearing hairs, on the dorsal side of the body, one on each side of the abdominal cleft (Plate XI, Fig. 3, b, c).

Mentum. A kind of secondary rostrum, or "under-lip," not altogether tubular, but rather a deepish trough, through which the rostral setæ pass after leaving the rostrum. It may have one, two, or three joints. It is not noticeable in the Diaspidinæ. (Plate I, Fig. 5, b.)

Metamorphosis. A change of form. For the number and characters of these see Chap. II.

Moniliform. Like a string of beads.

Monomerous. With a single joint.

Multilocular. With several divisions: a term applied to the spinneret orifices of some insects, distinguishing them from "simple" orifices, which show only a single tube. Multilocular orifices exhibit a bundle of tubes enclosed together. (Plate I, Fig. 4, c, d, p; Plate XVIII, Fig. 2, e.)

Nervure. A strong vein which, starting from the attachment of the wing of the male, runs along the anterior edge of the wing, a little within it: at about half its length a branch runs obliquely towards the posterior edge. (Plate I, 16; Plate XIX, f; Plate XXI)

Normal. According to rule—not exceptional.

Ocelli. Two, four, or six minute circular simple organs, on the head of the male: probably organs of vision. In the Monophlebidæ they would seem to be replaced by a smooth rounded protuberance behind the eye. (Plate i., Fig. 14, oc.; Plate VIII, Fig. 2, k, m; Plate XXI, Fig. 2, b.)

Ovisac. The cottony bag or nest formed by certain species of Lecanidinæ and Coccidinæ for the reception of their eggs. (Plate XII, Fig. 1, a, b, c; Plate XIX, a, b, c.)

Peduncle, pedunculated. A stalk; stalked.

Pellicle. The skin of an earlier stage, cast off at each metamorphosis; used by the Diaspidinæ and by one genus of Lecanidinæ in the formation of the puparium or test. (Plate I, Fig. 3, a, b; Plate VII, Fig. 2, b.)

Polymerous. Many-jointed.

Pupa. The last stage of the male insect before emerging winged.

Puparium. The shield, covering, or "scale" of the Diaspidinæ. (Plate I, Fig. 3, e; Plates iv., v., vi.)

Rostral setæ. Three or, in a few cases, four long, fine, curling, tubular bristles springing from the rostrum, and often passing through a mentum; used for insertion into the tissues of a plant and sucking their contents. (Plate I, Fig. 5; Plate VI, only one being here shown, from the smallness of the drawings.)

Rostrum. A more or less conical, tubular, projecting organ, or beak, protruding from the under-side of the cephalic region, or between the first pair of feet. It is absent in the adult female Cœlostoma. It is the "mouth" of the insect. (Plate I, Fig. 5; Plate IV, Fig. 5.)

Sac. The cottony, bag-like covering or nest produced by the spinnerets and concealing the insect in many of the Coccidinæ and some Lecanidinæ. (Plate XV, Fig. 1, c; Fig. 2, b.)

Scale. The shield or puparium of the Diaspidinæ. The word is commonly used to designate the outward appearance of insects of the whole family, which are indiscriminately called "scale-insects," although many of them form no shield whatever.

Secretion may be of various kinds. It is matter produced by internal organs, and expelled through the "spinnerets." In the Diaspidinæ the secreted portion of the puparium (that is, all except the pellicles) is made up of fine, closely-woven fibres, forming the "scale." In the Lecanidinæ it probably exudes originally as fine fibres, but these become agglomerated in some cases in a waxy or horny mass, or in others are loosely collected as cotton. In the Coccidinæ the secretion is usually cottony, or powdery like meal. Cœlostoma secretes all three—wax, cotton, and meal. In some instances, as in Carteria lacca, of Africa, the wax, called "shellac," is abundant enough to be commercially valuable; or, as in the Chinese Ericerus Pe-la it can be used for making candles.

Seta. A bristle—a long stiff hair.

Setose. Bearing a few bristles.