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. 47 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 SYRPHID^E. 



KK. Wings without a spurious vein. 

 L. Front with grooves or a depression beneath 



the antennae, p 476 CONOPID^E. 



LL. Front convex beneath the antennae. 



p. 470 SYRPHID^E. 



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. 



HlPPOBOSCID^E. 



BB. Both compound eyes and wings absent. 

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



parasite upon bats. p. 489 NYCTERIBIID^E. 



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

 like appendages, p. 489 BRAULID^E. 



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 



