SXRPlIIDvE. 25 



ending at wiug-tip ; in two sublamilies antl certain other genera 

 di]iped downwards into 1st posterior cell, sometimes conspicu- 

 ouslv so ; 1st ])osterior cell always closed by the ui)turned a[)ical 

 section of 4th vein; discal cell similarly closed by the apical 

 section of 5th vein, these two upturned endings generally more 

 or less parallel with the hind margin of the wing. Anterior 

 cross-vein before, at, or beyond middle of discal cell (which latter 

 is invariably present), ei'ect or strikingly oblique ; anal cell always 

 long, closed, at a short distance from \\ing-niargin. 1st basal 

 cell always distinctly longer than 2nd. 2nd longitudinal vein in 

 some few genera with bristly hairs on basal section. A so-called 

 vein or vena spuria is always present (except in Graptomyza^ and 

 is peculiar to this family. It is merely a chitinous fold in the 

 wing that runs diagonally along the 1st I)a.sa] cell from near the 

 origin of the 3rd vein, crossing the anterior cross-vein on its 

 lower half, dying away nenr lip of discal cell, gradually approach- 

 ing the latter. This false vein is sometimes very distinct, at 

 other times very faint. A second similar false vein occurs just 

 below the basal part of the 5th vein*. 



Life-history. The larvae are amphipneustic, apparently acepha- 

 lous, of about 11 uncertain segments, with rough skin, often 

 pigmented, especially in Si'Rraix.^ ; the posterior spirncles near 

 together at tip of body. Puparium with thoracic spiracle-horns, 

 and sometimes with smaller anterior horns that mark the position 

 of the larval spiracles. Abdominal spiracles in pupa also promi- 

 nent, much as in larva. Of many European species the metarao- 

 phoses have been adequately described and figured, 'S'^r/i/ufs ribesii 

 and pifrastri by De Geer, the latter again by Et'auiuur. and 

 IJeJo/ihilus peitdalvs by Walker; whilst Bouche, SchiifVer, Swam- 

 merdam, Van Roser and others have contributed to our know ledge 

 of the early stages in Syhpiiid^:. A large niimber of the species 

 are a])hidiphagous in the larval slate (Syrplnts etc.) ; others live 

 in decaying wood {Xylola etc.) or in the sap flowing from injured 

 tvtes {Brachyojiu etc.); some in decaying vegetable matter or in 

 dr&infi (ErisiaUs etc.) ; in stems oT plants or fungi (Chilosia) ; in 

 nests of the largi-r Hymeiioptera, such as Vcsjia and Bomhus 

 (Voh(ceUa). Some live in bulbs or in rotten onions (Merodon, 

 Eiivienis) ; Microdon in ants' nests ; whilst one species is 

 reputed to live in cow-dutig (]f7iinf/ia)f. A bibliography of the 

 biology was given by V. Brauer (.Systemat. Studien auf Grinidlage 

 der Diptereii-larven, in Denk. Ak. Wien, Math.-Xaturwiss. 

 Klasse, xlvii. 1883); while mon! recentiv C. L. Mctcalf has pub- 

 lished much infoi-mation on the biology of this family in a study of 



* Terrall stilted that lie tlioiiglif this secorul vein had not bet'ii reciu'ded 

 befoi'p, but Walker (In.-*. Brit. Dipt, ii, p. 2;i">)di8tincl])' notes them both. Some 

 pedantic author.'* have de.sired to throw out the ji^enus (Tr«y'A'»«//~rt, owini; to 

 tbeabsonce in it of the vriia spuria, but this nrenus is now universally recognized 

 as belonging to this family. 



t The above is mainly from Verrall, 'British Flies,' Syrphid;i', p. l.'!l. 



