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Show 274 INSECTA.. cupreous-v1. o1 e t; 1e gs bl ac k , with a white l'ing; wings long, with a brown spot. bl 1 Th 1 1 . . cow dung· the body forms an o ong ova, e arva 1ves In • ' . . d d ointed anteriorly, furnished With a squamous nat rowe .a n d P . h t hooks. The body · · d · h IS mtersperse w1t head provide w1t wo . . under its own skm, and Without any hairs. It becomes a pupa . f . · f r The perfect Insect Issues rom 1ts material change o torm. . , . d . . ff the anterior portion. See Reaumur, In-pnson by nv'lng o sect., IV, Mem., IV and I. . . R .. Me1S. eaumurn, ·g' · Differing from the c. uprarms m the t Of Wh'1 ch or at least the base, 1s of a blood-red, abdomen, mos ' or a brighter tint of the same colour( 1 ). VAPI'o, Lat. Fab.-Pachygaster, Meig. Only differing from Sargus in the an:ennre, which are still shorter, with the two first joints shorter or Wider, or altogether transver-sal(~). Our second general division of the Diptera, which are provided with a sucker enclm;ed in a sheath, and whose antennre consist of but three or two joints, comprises those whose pro· boscis usually bilabiate, long, geniculate, and bearing the palpi ~little above the elbow, is most commo~ly entirely contained in the oral cavity, and when always sahent, has a sucker composed of only t~o pieces. The last joint of th~ ~ntennre, always accompanied by a stilet or seta, never exhibits annular divisions. The palpi, when at rest, are concealed. This division will form our fifth family. ( 1) See the same authors. . . . 'Viedemann in bis "Analecta Entomologica," has figured a. Brazilian species, the S. furcifer: remarkable for the scutellum being armed with a. long spine, forked at the extremity. (2) See the same authors. DIPTERA.. 275 FAMILY V. ATHERICERA. Where the proboscis is usually terminated by two large lips. The sucker is never composed of more than four pieces, and frequently presents but two. The larvre have a very soft, extremely contractile, annulated body, narrowest and most pointed anteriorly. The head varies as to figure., and its external organs consist of one or two hooks . ' accompamed in some genera by mammillre, and probably in all by .a sort of tongue destined to receive the nutritious juices ~n whiCh they feed.. They usually have four stigmata, two situated on the first rmg, one on each side, and the two others on as many circular, squamous plates, at the posterior extremity of the body. It has been observed that these latter, at least ~n several~ were formed of three smaJier and cJosely approxImated stigmata. The larva has the faculty of enveloping these parts with the marginal skin, which forms a sort of purse. They never change their skin. That which invests them when first hatched becomes indurated, and thus forms a sort of cocoon for the pupa. It becomes shortened assumes an ovoidal or globular figure, and the anterior portion, which in the larva was the narrowest, increases in diameter, or is sometimes even thicker than the opposite extremity. Traces of the annuli, and frequently vestiges of the stigmata are observed on it, although the latter no longer serve for respiration. The body is gradually detached from the skin or cocoon, assumes the figure of an elongated and extremely soft ball, on. which none of its parts are perceptilile, and soon passes mto the state of a pupa. The Insect issues from its she! I, b! remo~ng with its head the anterior extremity, Whtch :fhes off hke a cap, that part of the cocoon being so disposed as to facilitate this result. |