MUSCIDEA BORBORID^E. 101 



27. Anal cell wholly wanting; face usually large and arched, with the 



mouth opening large EPHYDRID^E. 



Face not arched, and the mouth opening never remarkably large. 28 



28. Arista loosely and long plumose. . . . . DROSOPHILID^E. 

 Arista not plumose, or wanting. . . . AGROMYZID^E. 



29. Scutellum elongate, triangular, with protuberances or spines on its mar- 



gin; femora thickened. . . ... RHOPALOMERID.S. 



Flies without both the above characters. . /' . . 80 



30. Oral vibrissae present. . . . .... . . 31 



Oral vibrissae wanting . . . . . .'".,. 35 



31. Front bare or bristly at the vertex only (Piophilinn). . SEPSIDJE. 

 Front bristly at least as far as the middle 32 



32. Posterior cross-vein situated before the middle of the wing, the two 



cross-veins approximated. ..... AGROMYZID^E. 



Posterior cross-veins situated beyond the middle of the wing, the two 

 cross-veins not much approximated 33 



33. Arista bare; body short and broad (Milichince). . AGROMYZID.E. 

 Arista pubescent or plumose, or, if bare, the abdomen elongate. 34 



34. Arista with a few long hairs, mostly on the upper side. DROSOPHILHX*:. 

 Arista thickly short plumose, pubescent or bare. . GEOMYZID^:. 



35. Posterior basal and the anal cell of considerable size, distinct. . 38 

 Posterior basal and the anal cell small and indistinct. . . 37 



36. Front bristly on the sides. . . . . . . TRYPETID^E. 



Front bristly at the vertex only, or bare PSILID.X. 



37. Silvery white or whitish gray species, with unspotted wings; third 



antennal joint usually angula.ted on the upper angle. AGKOMYZIDJE. 



Reddish yellow or brownish red species, often with spotted wings ; 



third antennal joint rounded at the tip. . . . GEOMYZID/E. 



33. BOKBORIM!. 



Moderately large to small, black, brown or obscurely yel- 

 lowish flies, having a quick, short flight. Head hemispherical'; 

 face obtusely carinate in the middle ; vibrissae present ; front 

 broad, usually bristly. Antennas short ; third joint rounded, 

 the arista bare or pubescent. Second segment of the abdomen 

 with a transverse depression ; genitalia sometimes moderately 



