DIPTERA 789 



H. Scutellum without spinous protuberances, p. 835 



Xylophagid^ 



HH. Scutellum with two spinous protuberances, p. 834. . . 



COENOMYIID^ 



BB. Antennas consisting of not more than three segments; the third segment 



either with or without a style or an arista, but not divided into subsegments. 



C. Antennte consisting apparently of a single globular segment bearing a 



long, arista ; wings with some stout veins near the costal margin and other 



weaker veins extending across the wing unconnected by cross-veins 



(Fig. 1099). p. 847 Phorid^ 



CC. Flies that do not present the type of wing- venation represented by 

 Figure 1099. p 847. 



D. Cells M and ist M2 not separated. (See Figures 1094 and 1095, p. 844 

 for examples of this type of wing- venation). 



E. Vein R with a knot-shaped swelling at the point of separation of 

 veins R2 4- 3 and R4 4- s; the cross-vein r-m at or near this swelling 



when present; frontal suture absent, p. 843 Dolichopodid^ 



EE. Vein R with or without a swelling at the point of separation of 

 veins R2 4- 3 and R4 4- 5; the cross-vein r-m more remote from the 

 base of the wing; the frontal suture present. (Muscoidea). Pass to 

 Table B. 

 DD. Cells M (or 2d M) and ist M2 separate. 

 E. Radial sector three-branched. 



F. Venation intricate due to an unusual anastomosing of the veins 



(Fig. 1077) p. 836 Nemestrinid^ 



FF. Venation not of the type represented by Figure 1077. 



G. Vertex of the head distinctly hollowed out between the eyes; 



eyes never contiguous, p. 840 Asilid^ 



GG. Vertex of the head not hollowed out between the eyes; eyes 

 often contiguous in males. 



H. Alulets very large, p. 837 Acrocerid^ 



HH. Alulets small or rudimentary. 



I. Cell Mj present. 



J. Vein Rs ending before the apex of the wing. p. 842.. 

 Apiocerid^ 



JJ. Vein Rs not ending before the apex of the wing. 



K. Empodia pulvilliform. p. 834 Rhagionid^ 



KK. Empodia wanting, p. 839 Therevid^ 



II. Cell Mj obliterated by the coalescence of veins M3 and Cuj. 

 J. Third segment of the antennae without a style or an 



arista; vein Ali ending at or before the apex of the wing. 



p. 839 SCENOPINID/E 



JJ. Third segment of the antennae usually with a style or an 



arista; vein Mi ending beyond the apex of the wing. 



K. Vein Cu2 extending free to the margin of the wing or 



coalesced with vein 2d A for a short distance at the 



margin of the wing. p. 838 Bombylid^ 



KK. Vein Cu2 joining vein 2d A far from the margin of 

 the wing, often extending towards the base of the wing 



p. 845 Empidid^ 



EE. Radial sector with not more than two branches. 



F. Wings lanceolate and with no cross-veins except at the base. 



(Fig. 1097) p. 846 Lonchopterid^ 



FF. Wings not of the type represented by Figure 1097. 



G. Empodia pulvilliform. p. 837 Acrocerid.e 



GG. Empodia not pulvilliform. 



H. Vein Cu2 not coalesced with vein 2d A to such an extent as to 

 cause the free part to appear like a cross- vein. 

 I. Antennas with a terminal style or arista. 



J. Antennae with a terminal arista, p. 848 . Platypezid^ 

 JJ. Antennae with a terminal style. 



