PT.ECOPTERA OF NORTH AMERICA 



2r> 



showing it to be typically 5-branched in both fore and 

 hind wing. 



The branching of the vein Cul was as follows : 



No. of branches 2 3 4 5 6 



Times occurring, fore wing 1 35 55 6 3 



Times occurring, hind wing 19 70 11 



showing it to be typically 5-branched in the fore wing 

 and 3-branched in the hind wing. 



-M- 



2dA IstA Cu, 



M 

 Cu s Cu > 



2<*A- 

 Sth A 4thA 3 dA 

 Fig. 8. Wings of Acroneuria lycorias Newm. 



The crossveins in the median space were as follows : 



No. of crossveins 1234 5 6789 



Times occurring, fore wing 1 11 23 41 18 7 2 



Times occurring, hind wing.... 14 59 16 4 



In the forewing 6, in the hind wing 1, is the mode. 



The crossveins in the adjacent intercubital space 

 showed no such difference. 



No. of crossveins 5 6 7 8 9 10 



Times occurring, fore wing 5 13 38 32 9 3 



Times occurring, hind wing 8 20 39 22 9 2 



The genus Acroneuria takes its name from the presence 

 of extra crossveins in the portion of the wing beyond the 

 cord in the type species; but in A. lycorias such crossveins 

 were quite lacking in most specimens. In all 80 extra 



