4^6 THE STUDY OF INSECTS. 



J. Third segment of antennae without bristle or 

 style ; vein Vi ending at or before the apex of 



the wing (Fig. 568). p. 465 Scenopinid^e. 



JJ. Third segment of antennae usually with bristle 

 or style ; vein Vi ending beyond the apex of the 

 wing. 



K. Vein VII 2 extending free to the margin of 

 the wing or coalesced with vein IX for a short 



distance (Fig. 564). p'. 463 Bomby-lid^e. 



KK. Vein VII 2 joining vein IX far from the 

 margin of the wing, often extending towards 

 the base of the wing (Fig. 569). p. 466. 



Empidid^e. 

 EE. Vein III with not more than three branches. 



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



base (Fig. 572). p. 469 LoNCHOPTERiDiE. 



FF. Wings not of the type represented by Figure 572. 



G. Flies with a very small head ; with the thorax and 



abdomen inflated, giving the body a hunchback-like 



appearance, and with the alulets very large. The 



empodia pulvilliform, i.e., with three membranous lobes 



beneath the tarsal claws, p. 458 Acrocerid^e. 



GG. Head of ordinary size or very large ; form of thorax 

 and abdomen various ; alulets either large or small. 

 The empodia not pulvilliform, i.e., only two membra- 

 nous lobes beneath the tarsal claws. 

 H. Vein VII 2 appearing as a cross-vein or curved 

 back towards the base of the wing (Figs. 569, 588). 



I. Antennae with a terminal style or arista, p. 466. 



Empidid^;. 



II. Antennae with a dorsal arista. 



J. Proboscis rudimentary; mouth-opening small ; 



palpi wanting, p. 477 . . CEstrid^e. 



JJ. Proboscis not rudimentary ; palpi present. 

 K. Head with a suture immediately above the 

 antennae through which the ptilinum is pro- 

 truded and withdrawn (Fig. 587). p. 479. 



MUSCID^E. 



KK. Head without such suture, p. 466. 



EMPIDIDiE. 



HH. Vein VII 2 not coalesced with vein IX to such an 



