Vicinity of Mazon Creek, Illinois. 



359 



for the whole radial system is only the radius (s. str.) without 

 the sector, giving off some branches forward. What I thought 

 to be the media evidently is the long radial sector, rising near 

 the base and sending forth some long branches, directed 

 obliquely backward. A part of the veins designated by me 

 as belonging to the cubitus must therefore be attributed to the 

 media, which is not abundantly forked. The cubitus, too, 

 does not show a conspicuously rich embranchment. In the 

 posterior wing the sector seems to be much more expanded 

 and in consequence of this the media and cubitus are strongly 

 reduced ; the anal area is large and fan-like. Coxse of the 

 hind legs very large. 



Euc^enus Scudder. 



Eucoenus ovalis Scudder. Figs. 36-39. 



The Yale collection contains a male and two females of this 

 species which may be easily distinguished by the presence of 



Fig. 36. Fig. 37. 



Fig. 36. Eticwms ovalis. $ x 3. Fig. 37. Eiiccenus ovalis. ? x 3. 



