Labrum, or as it is sometimes termed labium superius, upper lip, a transverse moveable piece, placed immediately be low or underneath the clypeus and above the mandibles.
Labium, lip, termed by some entymo logists labium inferius, and by others mentum, or chin, a horny substance, sometimes truncate, and terminates the mouth ; beneath it supports the posterior palpi, and serves as a sheath for the tongue.
Ligula, a soft instrument, coriaceous at the base, often bifid at the tip, and re tractile ; this part is fbund only in insects provided with mandibles.
Gala, casque, two membranaceous, in articulate pieces, placed one on each side of the mouth in some insects of the hemtptera and neuroptera orders, and in conjunction with the lips covering the mouth ; this part is by some considered as an anterior palpi, or an exterior divi sion of the jaws.
In some insects the mouth is elongated into a tube, or placed at the end of a pro jection of the head, and is then either a lingua, proboscis, haustellum, rostellum, or rostrum.
Lingua, tongue, soft, flexible, tubular, involuted, like the spring of a watch, usually obtuse at its termination, and placed under the head betWeen the palpi oi' the butterflies and moths.
Proboscis, trunk, soft, retractile, inar ticulate, labiated at the extremity, and is peculiar to the flies ; the common fly af fords a good example of it.
Haustellum, sucker, composed of very fine and rigid filaments, enclosed in a bivalve sheath, and is peculiar to the cimices, and some of the flies.
Rostellum, a bill, or beak, coriaceous, articulate, and enclosing the haustelltim.
Rostrum, a prolongation of the head, terminated by the mouth, as in the cur culios, &c.
Some of these terms are not used by some authors as here defined ; and in deed so unsettled are many entomologi cal terms, that the student is often very much perplexed by the various applica tions of them.
II. Truncus, the trunk, to which the legs are attached, is situated between the head and the abdomen ; it is divided into, 1. The thorax, or chest, which is the superior part. 2. Scutellum, i. e. small shield or escutcheon, separated from it by a suture, on the posterior part. 3. The breast and sternum, which is the in ferior part.
III. The abdomen, that part which con- • tains the stomach, intestines, and other viscera, consists of several annular seg ments; it is perforated on the sides with spiracula, or breathing-holes; the upper part of it is termed tergum, or back ; the inferior part venter, or belly ; the pos terior part anus.
1V. Artus, the extremities, are the wings, legs, and tail.
(1.) Alm, the wings, are two or four ; they are either, I. Plana, i. e. plain, such as cannot be folded up by the insect : or, 2, Plitatiles, or folding, such as can be folded up by the insect at pleasure. 3. Er. cize, erect, such as have their superior surfaces brought into contact, and stand upright when the insect is at rest. 4. Parentes, spreading ; such as are extend ed horizontally. 5. Incumbentes, incum such as rest on the upper part of the abdomen 6. Deflex2e, bent down ; such as are partly incumbent, but have their exterior edge inclined towards the sides of the abdomen 7. Reversze, re versed ; such as are incumbent, but in verted. 8. Dentatze, such as have their edges notched or serrated. 9. Caudatw, such as have processes extended from their extremities like a tail. 10. Reticu laize, netted ; when the vessels of the wings put on the appearance of net-work. 11 Pictze, painted ; such as are marked with coloured spots. bands, streaks, lines, or dots, 12. IN otatx, marked with specks. 13. Ornatz, adornt d with little eyes, or circular spots, containing a spot of a dif ferent colour in their centre : the central spot is termed pupil ; the exterior one is called iris ; this may happen either in the primary or secondary wings, on their up per or under surfaces : the superior wing is called primary, and the inferior secon dary, to avoid confusion, as they may be at times reversed. The elytra are hard shells, occupying the place of the upper wings. They are for the most part move able, and are either, 1. Truncata, trun cated, when shorter than the abdomen, and terminated by a transverse line. 2. Spinosa, or prickly, when their surfaces are covered with sharp points or prickles. 3. Serrata, serrated, when their edges are notched. 4. Scabra, rough, when their surface resembles a file. 5. Striata, striated, when marked with slender lon gitudinal furrows. 6. Porcata, ridged, when marked with elevated ridges. 7. Sulcata, furrowed. 8. Punctata, marked with dots. 9. Fastigiata, when formed like the roof of a house. The hernelytra, as it were half-elytra, partaking partly of the nature of crustaceous shells, and membranaceous wings, being formed of an intermediate substance. Dalteres, or poisers, are small orbicular bodies placed on stalks, situated under the wings of in sects, of the orderDiptera.