DIPTERA. 427 



extent as to cause the free part to appear like a 

 cross-vein. 



I. Antenna with a terminal style or bristle. 



J. Antenna with a terminal bristle, p. 474. 



Platypezid^e. 

 JJ. Antenna with a terminal style. 



K. Front with grooves or a depression beneath 



the antennae, p. 476 Conopid^e. 



KK. Front convex beneath the antennae, 

 p. 470 Syrphid^e. 



II. Antenna with dorsal bristle. 



J. Head extremely large, and with nearly the en- 

 tire surface occupied by the eyes (Fig. 577). 

 p. 473 Pipunculid/e. 



JJ. Head not of the type represented by Figure 



577. 



K. Wings with a vein-like thickening, the spu- 

 rious vein, between veins III and V (Fig. 574). 



p. 470 SYRPHIDiE. 



KK. Wings without a spurious vein. 

 L. Front with grooves or a depression beneath 



the antennae, p 476 Conopidte. 



LL. Front convex beneath the antennae. 



p. 470 SYRPHIDiE. 



AA. Flies in which the abdomen is indistinctly segmented, and the 

 two legs of each segment are widely separated by the broad ster- 

 num. The adults live parasitically upon birds, mammals, or the 

 Honey-bee. 

 B. Compound eyes present ; wings present or absent, p. 487. 



HlPPOBOSCIDjE. 



BB. Both compound eyes and wings absent. 

 C. Halteres present ; tarsal claws of ordinary form. Adults 



parasite upon bats. p. 489 NycteribiiDjE. 



CC. Halteres absent; last segment of tarsus with a pair of comb- 

 like appendages, p. 489 Braulid^. 



Suborder ORTHORRHAPHA (Or-thor'rha-pha). 



The Straight-seamed Flies. 



To this suborder belong those families of flies in which 

 the pupa escapes from the larval skin through a T-shaped 



