31 



by a cross-vein connecting it with the stem of the 

 second anal without an evident intervening fork.- 

 dd. Basilar space (between the arculus and base of 

 wing) crossed by 2-6 cross- veins ; supratrian- 

 gular space with cross-veins; male anal triangle 

 3-5-celled. HI. Boyeria. 



d. Basilar space free or with a single cross-vein. 

 ee. Supratriangular space with cross-veins; 2 or 3 

 rows of cells between the radial sector and 

 the supplementary sector below it ; male anal 

 triangle 2-celled. IV. Bas'nesvhua. 



e. Supratriangular space free from cross-veins, one 

 row of cells between the radial and supple- 

 mentary sectors, male anal triangle 1- or 2- 

 celled. Gomphctsch na. 



a. Radial sector forked or branched beyond its middle, 

 supplementary sector diverging from it until three 

 or more rows of cells intervene between the supple- 

 mentary and the basal part of the posterior branch, 

 beyond which the supplementary curves rather rap- 

 idly upward toward the branch ; anal loop much as 

 in bh, the first anal reaching more than half way 

 (usually about two thirds) across the bottom of the 

 loop, and connected with the second anal by a short 

 oblique cross-vein, so that the anal loop appears 

 4-sided with a truncated inner hind angle ; triangles 

 of both wings 4- or 5-celled, inner side almost always 

 receiving a cross-vein. V. ^Eschna. 



t. Upper part of arculus much shorter than its lower part, its 

 upper sector arising about midway between the lower 

 sector and the median vein above ; radial sector emitting 

 a number of oblique branchlets on its posterior side, but 

 not regularly forked ; anal loop apparently 4-sided, the 

 first anal extending nearly across the bottom of the loop, 

 the connecting cross-vein very small and inconspicuous, 

 usually meeting the second anal at about a right angle. 



VI. Anax. 



