BRITISH FLIES 7 



annulations are considerably soldered together as in Btratiomys (fiL(. 19), or 



Fig. 18. — Cano'Diyiafi-irvr/iiua i. x 122. 



Fic. 10. — Slrutiomysfnrcala 9- x 8. 



Sargus (fig. 20), or Tahnnus (fig. 21), and in these the terminal style or 

 arista often becomes apparent. As a proof that these forms show a connect- 

 ing link from the Nemocei;a to the Athekiceka it may l)e noted that all 



Fig. 20. — Saryus iridatus $. x 30 



Fli:. ■IX.'-'I'oJhi ibVS inilumiiuliii 9' 



X 20. 



species with an annulated third antennal joint belong to the Eremocilkta 

 (those groups which exhibit no macrochtetpe) ; after the EREMopH.^iiTA the 

 third antennal joint is always solid (the Mydaichc have an apparently 



Fig. 22. — Bomhylius major <J. Fig. 23. — Thtrtjva nobilitata 9- 

 X 23. X 30. 



Fio. 24. — Asihis crabroniformis J. 

 X 22. 



jointed tlagellum of quite a distinct type) and the terminal style or arista (if 

 any) becomes more regular as in Bomhylius (fig. 22), or Thereva (fig. 23), 

 and when the Enekgopoda of Osten Sacken are reached and macrocha^tse 

 become the almost universal rule this is still more the case, as in Asihis 



