CLASSIFICATION OF INSECTS 325 



H. Third joint almost always with a dorsal arista ; a 



spurious longitudinal vein between the third and 



fourth longitudinal veins ; first posterior cell al- 



waysclosed. Flower-flies. (Fig. 463) SYRPHIDAE 



HH. No spurious longitudinal veins. 



/. Small ; hind tarsi enlarged and often orna- 

 mented in the male arista terminal. Flat- 

 footed flies PLATYPEZIDAE 



//. Small ; head large, composed chiefly of eyes ; 

 arista dorsal. Big-eyed flies. PIPUXCULIDAE 

 /. Squamae small or vestigial ; eyes never con- 

 tiguous ; the front in both sexes of equal 

 width ; thorax without complete transverse 



SUture ACALYPTERAE 



A". Auxiliary vein distinct, the first vein 

 ends near or beyond the middle of the 

 wings ; a distinct bristle on each side 

 of the face; oval vibrissae present ; front 

 usually with well-developed bristles and 



hairs CORDYLURIDAE 



KK. Front never bristly near the antennae ; 

 abdomen cylindrical, contracted near 

 the base. Small shining black flies. 

 Cheese-maggot, etc. . . SEPSIDAE 

 L. No oral vibrissae ; abdomen elon- 

 gate, often narrowly constricted , 

 proboscis long and folded near the 

 middle. (Fig. 462) . CONOPIDAE 

 LL. Upper fronto-orbital bristles only 

 present; preapical tibial bristle rarely 

 present ; arista rarely plumose ; ovi- 

 positor horny ; wings usually pic- 

 tured ORTALIDAE 



M. Fronto-orbital bristles present 

 or absent ; second joint of the 

 antennae often elongate ; arista 

 plumose ; preapical tibial bristle 

 present; ovipositor not horny; 

 wings often pictured. Meadow- 

 flies . . . SCIOMYZIDAE 

 MM. One or two fronto-orbital bris- 

 tles ; third joint of the antennae 

 more or less elongate ; preapical 

 bristle absent or present. All 

 small species. SAPROMYZIDAE 



