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Show INSECTA. 226 n· d h"s work on the tptera ticular, has well described th.em,da? th~ Mem. de la Soc. des · f "1.., pubhshe m · of the north o .1.· ranee d L ·ne of which he 1s one Sc. de 1' Agricult. et des Arts,b e lurp' asses, in my opinion, . . . bed mem ers, s of the most dtstlngms . h d this order of Insects. every th.m g h't th ert o pub h.s e on. t two prinC.i pal secti.o ns, . . 'd the Dl}ltera m o ~ We wtll d1v1 e h E lish sa vans, even torm as which in various systems of t e ng many particular orders. h fi , t the head is always dis-h. h mpose t e Is ' In those w tc co k . , enclosed in a sheath, and h the sue er IS tinct from the t orax, . 1 dentated. The rnetamor-h ta . are strop e or the hooks oft e rst 1 . lways effected after they phosis of the larvre into nymp 1S lS a have left the moth~r: . fi d Diptera whose antennre are In the first subdiVISIOn we n , multi-articulated. FAMILY I. NEMOCERA. uall consist of from fourteen to In this family the ante~re us . y to twelve in the others. . . d from SIX or ntne, ' sixteen JOm.tsh an :fiT form o; setaceous, frequently hairy, par· They are ett er 1 d h longer than the head. The ticula:ly in the males, ~n d ~~:nand rounded, the eyes large, body IS elon.gate~, the e; ither short and terminated by two the probosms sahent, an. e . h lt'ke rostrum with two . 1 ged mto a stp on- ' large hps or pro on . b lly filiform or setaceous 1 . · t d at 1ts ase usua exterior pa pt mser e fi . . ~ The thorax is thick and and composed o~ four or ve JOl~ s.e hal teres are entirely ex· elevated; the wmgs are oblong' th. d 'th alulre The ab· t1 accompame Wl · · posed and apparen y un 1 formed of nine annuh; domen is elongated, and most commlon yb t ·s till. cker at the end . · · t · the fema e u 1 it termulates 1n a P01n 10 . h '1 'The legs are very and furnished with hooks In t e ]rna esd b these Insects to long and slender and are frequent y use y lHPTERA. 227 balance themselves. Several, particularly the smaller ones, coiiect in the air in numerous swarms, and as they flit about form a sort of dance. They are found at almost every season of the year. In coitu they are united end to end and frequently fly in that position. Some of the females commit tlleir ova to the water; others deposit them in the earth or on plants. The larvro, always elongated and resembling worms, have a squamous head, always of the same shape, the mouth of which is furnished with parts analogous to maxillro and lips. They always change their skin to become nymphs. The latter, sometimes naked, and sometimes enclosed in cocoons constructed by the larvre, approximate in their figure to the perfect Insect, present their external organs, and complete their metamorphosis in the usual manner. They have frequently, near the head or on the thorax, two organs of respiration resembling tubes. This family is composed of the genera Culex and Tipula of Linnreus. Some in which the antennre are always filiform, as long as the thorax, densely pilose, and composed of fourteen joints, have a long, projecting, filiform proboscis, containing a piercing sucker eonsisting of five setre(l ). They constitute the genus CULEX, Lin.-Culicides, Lat. Or the Mosquetoes, where the body and legs are elongated and hairy; the antennre densely pilose, the hairs forming tufts in the males; the eyes large and closely approximated or convergent at their posterior extremity; the palpi projecting, filiform, hairy, as long as the proboscis, and composed of five joints in the males, shorter and appa- . (1) They have been well represented by Reaumur and Roffredi. The figure gtven by M. Robincau Desvoidy, in his Essai sut• la tribu des Culicides-M~m. de la Soc. d'Hist. Nat., III, 390-conveys a wrong idea of the disposition of these setz. This writer has promulgated an opinion relative to the correspondence of these parts with their sheo.tb, almost diametrica1Jy the reverse of that which is g-en~ rally received. Had he reflected that two of these setz, in the Syrphi and other D1ptera, are annexed to the palpi, he would not have taken them for mandibles but considered them as analogous to jaws. , |