212 Maine; agriculturai, expeirimsnt station. 1909. 



of the media is lost; in the third, Sciophilincs (fig. 72) the 

 M-Cu cross vein is wanting and R2+3 is crossvein-like in 

 appearance; while in the fourth, Mycetophilince (fig. 73) and 

 SciarincB, both the M-Cu crossvein and the vein R2+3 have 

 disappeared either by coalescence or atrophy. 



Below is given the Comstock-Needham terminology of wing 

 venation which is used in the following text, together with the 

 equivalent terms of the Schinerian system. 



Subcosta (Sc) 



r 

 I 



Radius 



Costa (C) = Costa. 



Sci = Subcostal or auxiliary vein. 



Sc2 = Subcostal crossvein. 



[ Radial sector 



. . .Ri = First longitudinal vein. 

 R2+3 = Anterior branch of third 



vein. 



I Ri+s = Posterior branch of third 

 ! vein. 



Media (M) = Fourth longitudinal vein. 

 Cubitus (Cu) = Fifth longitudinal vein. 

 Anal veins (A) = Anal and axillary veins. 



Crossveins 

 Subcostal (SC2) = Subcostal. 

 Radio-medial (R-M) = Anterior crossvein. 

 Medio-cubital (M-Cu) ^ Posterior crossvein. 



In this system each cell is given the name of the section of 

 the vein immediately in front of it ; thus the cell behind the 

 costa is called the costal cell (or C) ; the cell behind the basal 

 section of the radius is called R, that behind Ri is called Ri, 

 etc. In the case of Sciophilince where R2+3 is transverse in 

 position, the small cell is called Ri and the outer cell is R2+3. 

 Some writers, Winnertz among others, have erroneously con- 

 sidered the base of the radial sector as a crossvein, while they 

 called the true, crossvein the base of the third longitudinal vein 



(R.+O- 



In the past the characters most used for generic classifica- 

 tion have been derived from the wing venation while color 

 characters have been most used in describing species. In the 



