8 University of Michigan 



7. Anal area of the front wings one cell wide: Agriogomplius, Iscli- 



nogomphns, Microgomphus. 

 ja. Anal area of the front wings two or more cells wide: Cyanogom- 

 phiis, Bpigomphus, Leptogomphus, Macrogomphus. 



8. Two postanal cells in the hind wings: Agriogomplius, Cyanogom- 



pliiis, Ischnogomplms, Microgomphus. 



8a. Three postanal cells in the hind wings: Cyanogomphus, Epigom- 

 phus, Leptogomphus. 



8b. Four postanal, cells in the hind wings: Leptogomphus, Macrogom- 

 phus. 



9. Anal area in hind wings, distal to the postanal cells, two cells wide : 



Agriogomplius, Cyanogomphus, Ischnogomphus, Microgom- 

 phus. 

 9a. Anal area in hind wings, distal to the postanal cells, three cells 



wide: Bpigomphus, Cyanogomphus, Leptogomphus. 

 9b. Anal area in hind wings, distal 10 the postanal cells, four or more 

 cells wide: Macrogomphus. 



10. Anal triangle present in the male: Cyanogomphus, Leptogomphus, 

 Macrogomphus. 



loa. Anal triangle not present in the male: Agriogomphiis, Bpigomphus, 

 Ischnogomphus, Microgomphus. 



An Artificial Key to the Genera of the Group 



a. Basal antenodal of second series not present. 



b. One row of postrigonal cells in the front wings, Agriogomplius. 

 bb. Two rows of postrigonal cells in the front wings. 



c. Anal area in the front wings one cell wide, in the hind 



wings two cells wide Microgomphus. 



cc. Anal area in the front wings two or more cells wide, in 



the hind wings three cells wide Leptogomphus. 



aa. Basal antenodal of second series present. 



b. Anal area in the front wings one cell wide. .. .Ischnogomphus. 

 bb. Anal area in the front wings two or more cells wide. 



c. Distal thickened antenodal the fifth Cyanogomphus. 



cc. Distal thickened antenodal the sixth or more distal, 

 d. Anal area in the hind wings three cells wide. 



e. One cubito-anal cross-vein in addition to the 



inner side of the suhtTia.ng\e. . .Leptogomphus. 



ee. Two cubito-anal cross-veins in addition to the 



inner side of the subtriangle Bpigomphus. 



dd. Anal area in the hind wings four or more cells 

 wide Macrogomphus. 



