396 



4- Base of proboscis suddenly expanded into a 

 large onion-shaped bulb. 



5. Arista feathered on upper side only. 



Fig. 1 25 A. 



(2). Stomoxys calcitrans. Transverse section through about the middle 



of the -proboscis. The hypopharynx is kept in its place by the projecting 



ends of the labrum. The interlocking teeth of the labrum and labium 



are also shewn 



6. Male genitalia (hypopygium) highly charac- 

 teristic, oval and tumid, with a vulviform median 

 groove (anus) running from anterior margin to beyond 

 the middle. Sex" easily distinguished by this mark. 



7. Wings absolutely characteristic, especially in 

 the course of the fourth longitudinal vein (vide Fig. 



