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Show , 244 INSECT A. FAMILY II. TANYSTOMA. The Diptera of this family are distinguished from those of the two following ones by the last joint of the antennre, which, exclusive of the seta which may terminate it, presents no transverse division; the sucker is composed of four pieces. Their larvre resemble long and almost cylindrical worms, with a constant and squamous head, always provided with hooks or retractile appendages, by which they are enabled to gnaw or suck the alimentary matters on which they feed. They change their skin to undergo their second metamor· phosis. The nymphs are naked, and exhibit several of the external parts of the perfect Insect, which issues from its exuvire, through a slit in the back. In our first division we find species whose proboscis, always entirely (or nearly) salient, with the exterior· envelope or the sheath of the sucker solid or almost corneous, projects more or less in the form of a tube or siphon, sometimes cylindrical or conical, and sometimes filiform, and terminates without any remarkable enlargement, the lips being small or confounded with the sheath. The palpi are small. Some, that are rapacious, have an oblong body, the thorax narrowed before, and the wings incumbent, their proboscis is most commonly short or but slightly elongated, and forms a sort of rostrum. The antennre are always approximated, and the palpi apparent. AsiLUs, Lin. - Where the proboscis is dit·ected forwards. They fly with a humming noise, are carnivorous, voracious, and according to their size and power, seize on Flies, Tipulre, ~ombi or DIPTERA • . 245 CoJeopterre, which they then exhaust b . a small squamous head, armed with y suchon. Their larvre have earth, and tl. \!re become nym hs wt;o movable ~ooks, live in the dentated hooks and the bd p ' ose thorax lS furnished with ' a omen with 11 • In some-.l.lsz T z ct·, L at.-the head is trsam a spmes. ral and distant, even in the mal d nsverse; the eyes are late-long as the head The . hes, an the proboscis is at least as · wmgs ave a 1 . an elongated triangle near th . comp ete cubital cell, forming d an term.m at.m g at the t e. mternal rna rg·m -the last of all bearded. pos eriOr edge. The epistoma is always Sometimes the tarsi terminate b mediate pelJets. y two hooks, with as many inter- Here, the terminal stilet of the ante . or when it is very distinct I't nnre lS but slightly apparent · h ' s second and J t · · . ' 1D t e form of a seta. as JOlDt Is not prolonged There are some of these in wh. h than the head; their stilet is barellc .t~belantennre are hardly longer P om• t e d ; the part of the head f. Y v1s1 . e or ve ry s h ort, com. cal and t 1om wlnch the · · nen ' or but slightly so. y arise lS not promi- LAPHRIA, Meig. Fab. ~here the stilet of the last . oint f fusiform or resembles a small ;btuseo h the ~ntennre, which is either and where the proboscis is s!raight(l).ead, lS not (or barely) visible, ANOILORHYNoHus, Lat. Where the stilet of the antennre . where the proboscis has the for lS ~ardJy salient and pointed, and hooked rostrum(2). m o a compressed, arcuated, and DASYPoGoN, Meig. Fab. • Where that sti'l et I·S very distinct and conical · and th . 1s straight(3). ' e proboscis ((1) See Lat., Gen Crust et I '* 2 ) T~o spect. es c·o llecte·d byn Cseoc t, tI V~ 2. 98·, .M e t· g., Fab., Wied., and Macq. East Indtes. un eJean m Dalmatia, and another in the (3) See the authors already quoted. |