449 



Tabular Summary — coniinued 



No quadrangle 

 triangles 



or No quadrangle 

 triangles 



Three simple anal 

 veins present 



Anal field not exten- 

 sively developed 



Head rounded ; of 

 considerable size 



Not known 

 Not known 

 Not known 



Not known 



orQuadran gle and 

 sometimes trian 

 gles present 



Anal veins represent- 

 ed by a single 

 vein 



Anal field not exten- 

 sively developed 



Large numbers of 

 rows of cells be- 

 tween all longi- 

 tudinal veins, the 

 rows extending far 

 proximad 



Not known 



Not known 

 Not known 

 Not known 



Not known 



Anal veins repre- 

 sented by a single 

 vein 



Anal field often ex- 

 tended, but not 

 braced by loop 



Decided reduction in 

 number of rows 

 and a decided re- 

 treat distad, leav- 

 ing but few rows 

 between the prox- 

 imal portions 



Head rounded and 

 of c n s i derable 

 size 



Eyes dichoptic in all 

 families 



Labium cleft 



Abdomen s 1 e n der, 

 occasionally swol- 

 len at tip; superi- 

 ors leaf-like or 

 foreipate 



Inferior anal ap 

 pendages separate 



Quadrangle always 

 present ; triangles 

 sometimes present. 



Anal veins repre- 

 sented by a single 

 vein. 



Anal field extensively 

 developed or re- 

 duced ; when ex- 

 tended often 

 braced by loop. 



Still further reduc- 

 tion and retreat 

 distad. 



Head angular; often 

 widened. 



Eyes dichoptic or 

 holoptic. 



Labium cleft or en- 

 tire. 



Abdomen s 1 e n d er, 

 Zygoptera, or 

 thickened, Anisop- 

 tera ; s u p e r i rs 

 leaf -like, foreipate, 

 or reduced to tu- 

 bercles. 



Inferior anals fre- 

 quently united in 

 Anisoptera. 



