FUNGUS GNATS OF NORTH AMERICA. 253 



jj. Subcostal vein not produced far beyond the 

 base of the radial sector; petiole of the 

 media less than i as long as the anterior r" 



branch. (Fig. 179). /lo. Boletina. ^ 



hh. The distance between the tip of the subcostal vein 

 to the base of the radial sector is at least 1-4 the 

 breadth of the wing at the widest part. (Fig. 

 193). (Neoglaphyroptera). ^ ii. Leia.i-7'^ c 



gg. Cubitus forks distad of the media, ocelli in a trans- 

 verse row on the broad front, 

 h. Subcostal crossvein proximad of base of Rs. 



(Fig. 209). 12. Phthinia. '^^ 



hh. Subcostal crossvein distad of base of Rs. 



Megalopehna (See 12, Phthinia fraudulenta). 2-^/ 

 ff. Subcostal crossvein (Scj J absent. 



g. Cubitus forks proximad or under fork of the media, 

 h. Anal vein produced to the margin (Fossil). 



13. Sackenia. J- ' '' 

 hh. Anal vein not produced to the margin. (Fig. 243). 



10. Boletina, pt. ^ , 



gg. Cubitus forks distad of the fork of the media. 



h. The lateral ocelli remote from the eye margin; 



the posterior basal seta of hind coxa absent. p- 



(Fig. 210). / 14. Coelosia.t^ ^ ^ 



hh. The lateral ocelli close to the eye margin; sub- 

 costal vein short only rarely reaching costa; 

 posterior basal seta of hind coxa present. 



24. Phronia, part. 

 <M. Subcostal vein if long then ending either in Ri or with its "" 



end free, usually short. 

 e. Costal vein extends noticeably be3'ond tip of Rs (if but 

 slightly then the subcostal vein is long and ends in Ri)- 

 f. Lateral ocelli separated from the eye margins by a dis- 

 tance sub-equal or greater than the diameter of the 

 ocellus ; posterior basal seta of hind coxa wanting, 

 g. Subcostal vein at least i as long as the basal cell R, 

 and ends free orinRi. (Fig. 213). 15. Syntemna. - 

 gg. Subcostal vein less than J as long as the basal cell R; 

 base of fork of cubitus proximad of base of the 

 R-M crossvein; anal vein very short. (Fig. 216). 



16. Megophthalmidia. 



ii. Lateral ocelli nearly or quite continuous to the eye 



margin. 



g. Subcostal vein less than I the length of the basal cell 



R and ending in Ri, costa produced far beyond the 



tip of Rs; posterior basal seta of hind coxa absent. 



(Fig. 217). 18. Anatella. 



