DIOPSIDJE 8EPSIDJE. Ill 



1(5. Clypeus profriinent. 17 



Clypeus hidden 18 



17. The costal vein reaches to the third longitudinal vein. 



BKACHYDEUTRA LiOCW. 



The costal vein readies to the tip of the fourth longitudinal vein. 



PARYDRA Stenhammer. 



18. Claws almost straight ; pulvilli indistinct. . . EPHYDRA Fallen. 

 Claws curved ; pulvilli distinct 19 



19. Oral border quite bare ILYTHEA Halliday. 



Oral border with bristles. 20 



20. Arista pubescent. SCATELLA Desvoidy. 



Arista pectinated. C^ENIA Desvoidy. 



39. DIOPSID^E. 



Small species. Head prolonged into two lateral processes 

 hearing the eyes ; front bristly on the upper part only ; no 

 vibrissae on the border of the mouth. Front femora thickened. 

 Auxiliary vein much approximated to the first longitudinal 

 vein. 



But a single species of this family, Sphyracephala brevicor- 

 nis Say, is known from North America, and it will be easily 

 enough recognized by the singular eye-stalks. The habits, 

 whether of the adult or larval stage are not known, nor are 

 they known of any other member of the family, so far as I 

 am aware. 



40. SEPSID^. 



Head rounded ; front bristly above ; face perpendicular or a 

 little retreating; border of the mouth more or less hairy, with 

 or without vibrissae; proboscis short; antennae not porrect, 

 usually short. Abdomen narrowed at the base ; hypopygium 

 prominent. Auxiliary vein present or absent ; all the basal 

 cells distinct. Middle tibiae with spurs ; tibiae usually with- 

 out preapical bristle. 



The flies belonging to this family are usually small, black 



