HARDWICKE'S SCIENCE-GOSSIP. 



103 



2. Costal vein diminishing and not attaining tip of wing ; 



scutellum generally spined : Stratioinyidie. 



2.2. Costal vein extended round tip of wing in nearly 



uniform width ; scutellum rarely spined. 



3. Alula; large and distinct : Tabanidie. 



3.3. Alulae very small : XylophagidiE. 



I.I. Third antennal joint unringed ; style or bristle, when 

 present, dorsal or terminal ; third longitudinal vein 

 forked or simple. 



4. Antennal style or bristle absent, or, when present, 



always terminal. 



5. Alulae very large: Cyrtidis. 



5.5. Alidae moderately large or small. 



6. Front and crown deeply indented ; eyes very prominent : 



Asilidce. 



6.6. Front and crown smooth, often elevated; eyes not 



prominent. 



7. Third longitudinal vein forked. 



8. From the discoidal cell, or from this and the posterior 



basal cell together, at most three veins emerge and 

 reach the border ; therefore, never more than four 

 posterior cells present. 



9. Third antennal joint without style or bristle: Scenopi- 



nida. 

 Third antennal joint with a style or bristle. 

 Anal cell always attaining the border, and there, either 



open or closed : BoinbyliJiF. 

 Anal cell never attaining the border, generally short 



and closed : Kmpidix (part). 

 From the discoidal cell, or from this and the posterior 



basal cell together, at least four veins emerge and 



reach the border ; therefore, at least five posterior 



cells present. 

 Three onychia to tarsus : third antennal joint with 



terminal bristle : Leptidte. 

 Two onychia only ; third antennal joint with terminal 



style : Tkerevidce. 

 Third longitudinal vein simple. 

 Wings lanceolate : Lonchoptcridie. 

 Wings always rounded at the tip. 

 Anal lobe of wing distinct. 

 Antennae with terminal bristle : Plaiypezida. 

 Antennae with terminal style {Conopina) : Conopida 



(part). 

 Anal lobe of wing rudimentary or absent. 

 Anterior basal cell short ; posterior united with discoidal 



cell : Dolichopidie (part). 



15.15. Anicrior basal cell long, reaching middle of wing; 



posterior separated from discoidal by a transverse 

 vein : EmpidiX (part). 



4.4. Antennal style or bristle always present and always 



terminal. 



16. Anal cell long. 



17. Proboscis horny, long, simple, or geniculated [My opines) : 



Conopidiz (part). 



17.17. Proboscis soft. 



18. A spurious vein generally present, running along the 



third longitudinal vein ; eyes moderately large : 

 Syrphidce. 



18.18. Spurious vein absent ; eyes very large : Pipuncrtlida, 



16.16. Anal cell short. 



19. Posterior basal cell united to the discoidal : Dolichopidiz 



(part). , 



19.19. Posterior basal cell separated from discoidal by a trans- 



verse vein. 



20. Proboscis and palpi always distinctly present : MuscidcE. 



20.20. Proboscis rudimentary; palpi rudimentary or absent: 



CEstridcs. 



12. StratiomyidiE. 



In the "Ent. Month. Mag." for April, 1889, I 

 gave a list of the British species of this family, with 

 analytical tables of genera and species. 



The venation of all the twelve genera is very 

 similar, and easily recognised. 



The flies chiefly inhabit damp grass, marshes, 

 aquatic plants, and more or less humid localities, the 

 larvse feeding on rotten fungi and decaying vegetable 

 matter. 



The life-histories of some of the commoner species 

 have been fully vrorked out. 



There are five sub-famihes, divided as follows : — 



Abdomen of five or six segments ; scutellum two-spined or bare. 

 Discoidal cell emitting three veins : P achy gastrins. 



Discoidal cell (or together with posterior basal cell) emit- 

 ting four veins. 



Species never metallic in colour ; always black or 



green, with yellow spots or bands. 

 Scutellum spined (except Netnotelus], 



Antennal style thin, long : Clitellarince. 

 Antennal style short, blunted: Stratioinyincc. 

 Species always metallic ; Scutellum unspined : i>argi>uF. 

 Abdomen of seven segments or more ; scutellum two, four, or 

 six-spined : Berina\ 



The Clitellarince are represented by Ephippiiiin, 

 Latr., and Oxyccra, Mg. ; the Stratromyina by 

 Slratio?nyia, Geoff., Odotttomyia, Mg., and Nemoteliis, 

 Geoff. 



PachygastrincB. — Pachygaster, Mg., three species; 

 none very common, P. ater, Pz., is easily identified 

 by the blackish basal half of the wing, whilst in P. 

 Leackii, Curt., it is nearly all whitish ; long 3 mm. 



ClitellarincT. — Ephippitim thoraciciim, Latr., is a 

 large black fly, with long brownish-black wings, 

 thick red pubescence on the dorsum, and a strong 

 large spine on each side of the thorax ; very rare ; 

 Coombe Wood. It is supposed to take two years to 

 reach maturity ; long 12 mm. 



Oxycera, Mg., is a genus of rather small black flies, 

 with bright yellow spots and bands at the sides and 

 tip of the abdomen, the first segment of which is 

 much contracted. 



They occur in the height of summer in long grass, 

 and are most frequently met with in Dorsetshire ; 

 long 3-5 mm, 



Slratiomyina:. — Large flat-bodied flies, bred in 

 stagnant water, and usually found in its proximity. 

 Abdomen black, marked with large yellow side spots 

 {Stratiomyia, Geoff.), or yellowish, with an angular 

 dorsal stripe {Odontomyia, Mg.) ; S. furcata, F. (long 

 11-13 mm.), and O. viridula, F. (long 6-8 mm.), 

 being the most common species. 



Sarginic. — Brilliant metallic-coloured flies, tolerably 

 common. S. cupraritis, L., is blackish, thorax and 

 abdomen metallic blue or green, or exhibiting both 

 colours ; wings with a brown suffusion below the 

 stigma ; legs thin, black ; long 7-9 mm. 



Microchrysa polita, L., is a small bright metallic- 

 green fly, with clear wings and black legs ; common ; 

 often occurring in London ; long 4 mm. 



Berime. — Per is, Mg. They are smaller than 

 Odoniotnyia ; in two species the abdomen is reddish 

 yellow, in the other three, blue-black ; occurs chiefly 

 in woods. 



13. XylophagidcB. 



Two genera are British (five species), all very rare. 

 Their flight is sluggish ; the larva are wood feeders, 

 and if more frequently searched for, the species 

 might possibly be bred. Zetterstedt bred more than 

 one species, I believe, in Scandinavia. 



The antennas are attenuated, and somewhat 

 approach those of the Nemocera in appearance, 

 Walker thinking the group a link between the two 

 great divisions Nemocera and Brachycera. 



Antennae ten-jointed : Xylophagus, INIg. 

 Antennae twelve-jointed : Xylemyia, Rond. 



