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Show 298 INSECTA. 'b' 11 but four annuli. The antennre are tremity, and exh1 1ts externa Y • d b a . . as long as the head or nearly so, and termmate y JOmt 1o nger than the penultimate. . . · 1 • • L' • particular section, m their arva state Certam spectes, Iormmg a . ) inhabit the body of various caterpilla:s which they destroy( 1 • • C . 1 ilre in which the seta of the antennre 1s We now pass to reop l • • . L' • . · . 1 mous Their tlurd J01Dt always 101 ms an evtdently ptlose or P u • . elongated palette, longer than the precedmg one. DEXIA, Meig. The Dexire have the general appearance of the Ocypterre, their abdomen being narrow and elongated, particularly in the males(2). MusoA, Lin. Fab. Meig.-Mesembrina, Meig. In Musca, properly so called, or the true ~ly, the abdomen is triangular, and the eyes are contiguous poster1orly, or closely ap-proximated in the males. . Here come most of those Flies whose larvre feed on carnon, meat, &c.; others of the same subgenus inhabit dung. They all resemble soft, whitish worms without feet, thickest and truncated at the t r·10r extremity and becoming gradually sm_aller towards the pos e 't one which ' terminates in a point furm. shed w1. t h two h oo k s, oppos1 e , . . with which they divide their aliment, and a.ccelerate 1~s decomposl-t 1. 0 n . The metamorphosis of these Insects 1s effected m . a few daysd. The posterior extremity of the abdomen of the females 1s narrowe a~d prolonged in the manner of a tube or ovipositor, by which she can insert her eggs. . M. vomitoria, L.; Rres., Insect., II, Muse., et Cui., lX, x. A large species; front fulvous; thorax black; abdomen glossy-blue with black streaks. This Insect enjoys the sense of smell to a high de~ree, atn-nounces its presence in our dwellings by a loud hummmg, and deposits its ova on meat. Deceived by the cadaverous .odour arising from the Arum dracunculus, L., when in flower, 1t also (1) This genus also·is in great confusion in the work of Meigen, and .consists of species with very different antenna: and wings, as is evident from hls figures. We have removed the Echinomyice and the Melanophora:; until the wo:k of Dr Desvoidy is published we will leave the other species in the genus Thclnna. (2) See Meigen. DIP'fERA. 299 leaves its eggs there. When the larva is about to become a pupa, it abandons the putrescent matters in which it has lived, which might then prove injurious to it, and penetrates, if possible, into the earth, or is metamorphosed in some dry and retired spot. M. cceaar, L. Body, a glossy golden-green; legs black. The female deposits her eggs on carrion. M. domestica, L.; De Geer, Insect., VI, iv, 1-11. The thorax of the Common Fly is of a cinereous-grey with four black streaks; abdomen blackish-brown spotted with black, and yellowish- brown above. The five last abdominal annuli of the female form a long and fleshy tube which she introduces, in coitu, into a slit situated between the pieces furnished with hooks, that terminate the abdomen of the male, and characterize his sex. The larva lives in warm and moist dung(l). SAROOPHAGA, Meig.-Musca, Lin. Fab. Only differing from Musca proper by the eyes being remarkably distant in both sexes. The ova are sometimes hatched in the venter of the mother-these species are called viviparous. 8. carnaria; Musca carnaria, L.; Mouche vivipare, De Geer, Insect., VI, iii, 3-18. Rather larger and more elongated than the vomitoria; body cinereous; eyes red; streaks on the thorax and square spots on the abdomen, black. The female is viviparous and deposits her larvre, which fill the cavity of her abdomen, on meat, carrion, and sometimes in wounds in the human body. By strongly pressing the abdomen of the male, a bowel-like body of a transparent white may be made to protrude, which has a vermicula1· motion that is continued even after the Insect has been cut in two(2). We will terminate the Creophila with genera which form a contrast with the preceding ones, either in certain peculiarities of the head, or by the situation of the wings, or the cells of their posterior extremity. The seta of the antennre is pilose in most of them. In some, such as the two following subgenera, the wings termi- (1) See Meigen: certain species that are more hairy form his genus Me1embrina. (2) See M:eigen. |
