248 NEW YORK STATE MUSEUM 



Limnobia, Geranomyia, Dicranomyia in part and Rhipidia.® 

 ee Sc atrophied, Rs long and straight to its origin 

 / Rs two branched; cross veins r and m present, Cu and" u? A 

 not fused beyond the base, wing widest just before the 



cord Antocha 



yf tis unbranched : cross veins r and m wanting. Cu and ist A 

 fused for a long distance at base, wing widest just beyond the 

 cord Toxorrhina 



a I find no venational characters that will separate this group of genera. Rhipidia is 

 well distinguished by the possession of pectinated antennae in the male; Geranomyia, by 

 the possession of a rostrum as long as the body; and while the length of Sc has been used 

 to separate Limnobia from Dicranomyia, it is not a sure criterion, for all sorts of inter- 

 gradations occur. In the former Sc is rarely reduced as far as the base of Rs, and in the 

 latter Sc rarely extends a little beyond the base of Rs. Clearly Dicranomyia is pcly- 

 morphic, as this key indicates, and as has before been pointed out in my discussion of D. 

 cinerea Doane. Perhaps it has become a little more so new by my addition to it of 

 ?D. whartoni. This soecies has nothing to do with D. cinerea, but represent 

 (after D. longipennis O. S.) the extreme cf vein reduction alorg another line. 



