212 MAINE AGRICULTURAL EXPERIMENT STATION. I909. 



of the media is lost; in the third, Sciophilincc (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 

 Sciarincr, 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. 



Costa (C) = Costa. 



c^ , . /<r^ X f Sci ^ Subcostal or auxiliary vein. 



Subcosta (Sc) ^ c u ^ i • 



! 0C2 = bubcostal crossvem. 



„ ,. [ Ri = First longitudinal vein. 



jA.adms ' 



I Radial sector [ R2+3 ^ Anterior branch of third 



vein. 



I R4+5 =r 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 Sciophilincc where R243 is transverse in 

 position, the small cell is called Ri and the outer cell is R24-3. 

 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 



