236 



NORTH AMERICAN DIPTERA 



Pho.id* II.-8. 9. Eeitom.via spinosa. dorsal and lateral views; 1'^. P'^^V'P'?"^', ^J' 

 Triphleba; 12. Aneurina; 13. Pulicophora ; 14. Chonocephalus. head of ? : lo. Beckenna. head 

 showing bristles. 



