788 AN INTRODUCTION TO ENTOMOLOGY 



L. Cross- vein m-cu present, p. 820. . .Bibionid^ 

 LL. Cross- vein m-cu wanting, p. 821 .ScATOPSiDiE. 

 KK. Antennae usually longer than the thorax; legs 

 slender and usually with greatly elongate coxag. 

 L. Vein m-cu present, the first branch of the radial 

 sector, vein R2 + 3, arising slightly proximad of 



vein m-cu. (Mycetobia) p. 797 ANisopiDiE 



LL. Vein m-cu present or absent, when present the 



forking of the radial sector is distad of it. 



M. Eyes rounded or oval. p. Sio.MvcETOPHiLiDiE 



MM. Each eye with a narrow expansion, the two 



expansions extending behind the antennas and in 



front of the ocelli, and meeting on the middle line 



of the head or nearly so. 



N. With tibial spurs; larvas with well-developed 



head (Sciarinas) p. 812 Mycetophilid^ 



NN. Without tibial spurs, larvee with a poorly 

 developed head (Lestremiinas). p. 816 



CeCIDOMYIID/E 



JJ. Ocelli absent. 



K. Antennae short, not clothed with long hairs, and with 

 most of the segments wider than long; wings very 



broad, p. 821 Simuliid^ 



KK. Antennae either bushy, being densely clothed with 

 long hairs, or slender with narrow segments; wings 

 nariow or moderately broad. 



L. Wing-veins well-developed on all parts of the wing 



M. Vein Ri ending at or near the end of the second 



third of the costal margin, p. 828. Thaumaleid^ 



MM. Vein Ri ending on the outer margin of the 



wing. p. 800 DixiD^ 



LL. Wing veins much stouter near the costal margin 

 of the wing than elsewhere, p. 8o2.Chironomid^ 

 CC. Antennae either consisting of four or five distinct segments or consisting 

 of five or more segments, with those beyond the second more or less closely 

 consolidated so as to appear as a single segment consisting of several sub- 

 segments. (Figs. 985, 986); cell 1st A closed by the coalescence of the 

 tips of veins Cua and 2nd A, or greatly narrowed at the margin of the 

 wing; palpi rarely elongate, and composed of from one to three segments. 

 D. Antennae consisting of foiu* or five distinct segments, empodia 

 wanting or bristle-like. 

 E. The first branch of media terminating at or before the apex of the 



wing. p. 842 M YDAID^ 



EE. The first branch of media terminating on the outer border of the 

 wing. 



F. The vertex of the head sunken, the eyes bulging and never con- 

 tiguous, p. 840 ASILID^E. 



FF. The vertex of the head plane or convex, the eyes not bulging; 



eyes of males often contiguous, p. 838 Bombyliid.e. 



DD. Antennae consisting of five or more segments but with those beyond 

 the second more or less closely consolidated; empodia resembling 

 pulvilli in form. 



E. The alulets large, p. 829 Tabanid^e 



EE. The alulets small or vestigial. 



F. The branches of radius crowded together near the costal margin; 



tibiae without spurs, p. 830 Stratiomyiid^ 



FF. The branches of radius not crowded together near the costal 

 margin; at least some of the tibias with spurs. 



G. Cell M3 closed, p. 832 XYLOMYIIDyE 



GG. Cell M3 open. 



