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Show 60 INSECTA. Fabricius, anticipate d l·n thi's point by Reaumur, divides the · Libellul~ into three genera. . · LrBELLUL~, Fab. . 1 h e the wings are extended horizontally Or L1bellu a proper, w er . · h t t The head is almost globular, Wlth very large, contl· w en a res · . t d eyes and a ves.i cular e1 e vat1· 0n on th e guous or closely approx1ma e ' . 11 • 11 ch side· the other or anter1or oce us vertex with an oce us on ea ' . . . ' I 1 The middle division of the labiUm Is much 1s muc 1 arger. 1 't d' smaller than the lateral ones(l), which unite beneath by~ ong~ u I· na1 suture, an d c l os e the mouth exactly. The abdomen IS ens1form and flattened. . The larvre and the nymphs have' five appendage~ at the ~oster10r extremity of the body, forming a pointed tail; thei~ body IS sho~t, the mentonniere convex, in the form of a helmet, w1th the two pm· cers resembling shutters. L. depressa, L.; Rres., Insect. A~uat., VI, _vii, 3. Brown somewhat yellowish; base of the wmgs black1sh; two yellow Jines on the thorax; abdomen ensiform, sometimes brown, and at others slate coloured, with yellowish sides(2). ..d!.sHNA, Fab. The .£shnre re3emble the Libellulre proper in their mode of bear· ing their wings, and in the form of their head, but ~hei: two poste· rior ocelli are placed on a simple transverse elevation m. the form of a carina. The intermediate lobe of the labium is also larger, and the two others are distant and armed with a very stout tooth and spiniform appendage. The abdomen i!i always narrow and elon· gated. The body of the larvre and the nymphs is also more elongated than that of the Libellulre in the same states. The mask is flat, and the two pincers are narrow, and have a small movable nail at the extremity. (1) These lateral divisions or palpi present a remarkable difference in the three subgenera. . . (2) For the other species, see Fabricius, Entom. Syst., and Latreille, H1st Gener. des Crust. et des Insect., XII, p. 10, et seq.; but particularly the Monographs of the Insects of this family, from the environs of Bologne, publish.ed in Latin by M. Van der Linden, that which he has since given on the spec1es of Europe, and finally another Monograph of European Libellula:, forming a part of the already quoted work of M. Toussaint Charpentier. ' NEUROPTEUA. 61 The abdomen is terminated by f.ve appe'ndages, but one of them is truncated at the end • JE. grandis; Libellula grandis, L.; Rres. Insect. Aquat., VI, iv. One of the largest species of this family, being nearly two inches and a half in length; fulvous-brown; two yellow 'tines on each side of the thorax; abdomen spotted with green or yellowish; wings iridescent. It darts with amazing rapidity over meadows, and along the shores of rivers, &c., pursuing flies in the manner of the Swallow( 1 ). AGRION, Fab. Where the wings are elevated perpendicularly when at rest, the head is transversal, and the eyes are distant. The form of the labium is analogous to that of the ..tEshnre, but the intermediate lobe is divided in two, down to its base. The third joint of the lateral lobes is in the form of a membranous ligula. The antennre seem to be composed of but four joints. The forehead presents no vesicle, and the simple eyes are almost equal, and arranged in a triangle on the vertex. The abdomen is very thin or even filiform, and sometimes very long. That of the females has its posterior extremity furnished with serrated laminre • The body of these Insects, in their first and second states, is equally slender and elongated, and the abdomen terminated by three fin-like laminre. The ma'iik is flat, the superior extremity of the mentonniere being raised into a point in some, and forked o1· sloped in others; the pincers are narrow, but terminated by several dentations, and resemble hands. .fl. virgo; Libellula virgo, L.; Rres., Insect. Aquat., VI, ix. Golden-green or green-blue; superior wings sometimes either entirely blue or only in the middle, and sometimes of a yellowish- brown. The mentonniere of the larvre and nymph is sloped like a lozenge at the extremity, and terminated by two points. .!l.puella; Libellulapuella, L.; Rres., lb., x, xi. Very various as to colour; its abdomen is most commonly annulated with black, and the wings are colourless. The superior extremity of the mentonniere of the Iarvre and nymphs forms a salient angle(2). (1) See the same works. The .TEshna forcipata might form another subgenus. (2) For the other species, see Fabricius, Entom. Syst.; Lat., IIi st. Gener. des ()rust. et des Insect., XIII, p. 15; Oliviel', Encyc. M6thod., article Libellule; and especially the preceding Monographs, where the variety of species and of their |