34 DURHAM DIPTERA. 



123 (128). X.5 2 placed before the middle of the wing, the two 



X-veins, X.4. and X.5 2 very near to the base of 

 the wing, and exceedingly near to one another ; 

 or, no X-vein on V.5. 



124 (127). X.5 2 immediately under X.4., or nearer to the base of 



the wing; or, X.5 1 and X.5 2 both absent (V. 38). 



125 (126). Arista bare or nearly so. Phytomyzid^e (LIV.) 



126 (125). Arista with long hairs on one side. Astiad^e (LV.) 



127 (124). X.5 2 always present, and placed further from the 



base of the wing than X.4. 



Agromyzid^i, part (LIII.) 



128 (123). X.5 2 at or beyond the middle of the wing; X.4. 



and X.5 2 neither very near to the wing base nor 

 to one another. 



129 (130). The arista bare. Body short and broad. 



Milichidje (LII.) 



130 (129). The arista plumose, combed, or distinctly pubescent, 



or, if bare, then the body always narrow and long. 



131 (132). Arista thinly but long haired, plumose or combed. 



Drosophilime (L.) 



132 (131). Arista thickly and short haired, pubescent, or bare, 



GEOMYZIDiE (XLVIII.) 



133 (118). Mouth bristles absent. 



134 (137). 0.5 1 and O.6 1 large and very prominent. 



135 (136). Antennas moderately long or very long, male geni- 



talia not prominent. Psilidje, part (XXXIX.) 



136 (135). Antennas short, male genitalia prominent, club- 



shaped. 580. Tetanura, Fin. 



(2522. pallidiventris, Fin.) 



137 (134). 0.5 1 and O.6 1 small and not very prominent. 



138 (139). Light grey or silvery species. 



Agromyzid-jE, part (LIII.) 



139 (138). Orange or brownish-red species. 



Opomyzid^e, part (XLV.) 



140 (26). Wings with two short very thick veins in the upper 



basal region from which spring a few very fine 

 unbranched veins. X-veins apparently absent 

 (V. 35). Phorid^e (LVII.) 



