29 2 THE STUDY OF INSECTS 



II. Third segment usually with style or arista; Mi ending beyond 

 the apex of the wing. 

 J. First branch of the cubitus extending free to the margin of 

 the wing or coalesced with the vein 2d A for a short dis- 



tance a1 the margin of the wing. p. 308 Bombyliid^ 



JJ. First branch of the cubitus joining 2d A far from the margin 

 of the wing, often extending to the base of the wing. p. 311. 



Empidid,e 



FF. Radial sector with not more than two branches. 



G. Wings lanceolate (Fig. 552). p. 312 Lonchopterid,e 



GG. Wings not of this type. 



H. Vein Cu 2 not coalesced with 2nd A to such an extent as to cause 

 the free part to appear like a cross- vein. 



I. Antennae with terminal arista, hind tarsi often broad and flat. 



( Fig. 495) Platypezida 



II. Antennae with dorsal arista; or in some cases, a terminal style. 

 J. Head extremely large; entire surface nearly occupied by eyes. 



(Fig- 555)- P- 313 Pipuncuud^e 



JJ. Head not of the type represented by figure 555. 



K. Wing with a vein-like thickening, the spurious vein, 

 between veins R and M; if wanting then front convex 



beneath antennae (Fig. 556). p. 314 Syrphid^e 



KK. Wing without spurious vein; front with grooves or a 



depression beneath the antennae Conopidce 



HH. Vein Cu 2 appearing as a cross- vein or curved back toward the 

 base of the wing (Figs. 550, 551). 



I. Frontal suture absent; antennae in most cases with a terminal 



style or arista, p. 31 1 EmpididjE 



II. Frontal suture present; antennae with dorsal arista. 



J. Alulae or calypteres small or rudimentary; subcostal vein 

 often indistinct or vestigial but often well preserved; vein 

 Ri rather short; thorax without complete transverse suture; 

 abdominal spiracles in most cases in the conjunctiva. Aca- 

 lyptratae including Agromyzid^e, p. 318, Piophilid,e, p. 316, 

 DiopsidcE, Psilid^e, p. 317, ChloropiDjE, p. 317, Ortalieme, 

 p. 315, Trypetid^e, p. 315, Sapromyzida, etc. 

 JJ. At least the lower lobe of the calypteres or alulae well de- 

 veloped; subcostal vein distinct for its whole course; trans- 

 verse suture complete; abdominal spiracles in most cases in 

 the lower margin of the tergites. 

 K. Proboscis much reduced or vestigial, not functional; 

 mouth-opening small (bot-flies). 

 L. Cell R 5 wide open in the margin (horse bots), p. 319. 



Gasterophilid.e 



LL. Cell R 5 nearly closed in the wing margin, p. 320. 



CEstriDjE 



KK. Mouth-opening normal; mouth-parts functional. 



L. Hypopleura (sclerite below the posterior spiracle and 

 above hind coxae) bare or with only some fine hairs. 

 M. Cell R 5 very slightly or not at all narrowed in the 

 wing margin. 

 N. Alulets rather small, lower one not projecting notice- 

 ably beyond the upper; under surface of the 

 scutellum without short, fine hairs; anal vein not 

 suddenly flexed up toward the end. (Scatophagidas). 



p. 318 CORDYLURID^E 



NN. Alulets larger, the lower one projecting beyond the 

 upper, or if small, either there are short hairs on 

 the lower surface of the scutellum or the second 

 anal vein is short and suddenly flexed up toward 



the end. p. 319 Anthomyid;E 



MM. Cell R 6 much narrowed in the wing-margin; arista 



plumose in most cases, p. 323 Muscid>e 



LL. Hypopleura with one or more vertical series of strong 

 setae. 



