64 



The Ottawa Naturalist. 



[June 



EXPLANATION OF PLATE. 



2, 24 and 26 on a larger scale thai 



(Fig. 1 IS on a smaller scale, Figs. 

 the others). 

 Pig. 1. Hind wuig of one ot the Anisoptera, Hagenius brevistylus. 



O. 

 P. 



Q- 



R. 



S. 

 T. 

 U. 

 V. 

 W. 



Postcubitals (1.3 m the 



series, 11 in the second). 



Nodus. 



Pterostigma. 



Basilar space. 



Supra-triangular space. 



Median space. 



Internal triangle. 



Triangle. 



Anal Triangle. 



tirsi 



A. Costa. 

 B Snbcosta. 



C. .Median Vein. 



D. Submedian Vein. 



E. Postcosta. 



F. Principal Sector. 



G. .Nfodal Sector. 

 H. Subnodal Sector. 



I. Median Sector. 



J. Short Sector. 



K. Upper Sector of the triangle. 



L. Lower Sector of the triangle. 



M. Arculus. 



N. Antecubitals (14 in the first 

 series, 13 in the second, the 

 first and seventh of the for- 

 mer coincident respectively 

 with the first and sixth of the 

 latter). 



Fig. 2. testes rectangularis male, abdominal appendages, dorsal view. 



3. Gomphus vastus, male, " " lateral view, 

 (a'ter Kellicott). 



4. Gomphus brevis, male, " " dorsal view. 



5. " " male, " " lateral view. 



6. " exUis, male, " " dorsal view. 



7. " " male, " " lateral view. 



8. " corniitiis, male, ■ '" " dorsal view. 



9. " " male, " " lateral view. 



10. N eiirocordulia yamaskanensis, male, abdominal appendages, dor 



sal view. 



11. Tetragoneuria cynosura, raaXe, 



12. " " male, " 



13. " canis, male, 



14. " " male, 



15. Helocordulia Uhleri, male, 



(after Martin). 



16. Helocordulia Uhleri, male, 



(after Martin). 



17. Dorocordulia libera, maXe, 



18. Leucorhinia intacta, male, 

 IQ. " intacta, female, terminal segments of 



below, showing vulvar lamina (v.). 



20. Leucorhinia hudsonica, male, abdominal appendages, lateral view. 



21. " hudsonica, female, vulvar lamina (v.). 



22. Sympetrum ricinum, male, abdominal appendages, lateral view. 



23. " rubicundulum. male, abdominal appendages, lateral 

 view. 



24. Sympetrum rubicundulum, male, left genital hamule. 



25. " " female, vulvar lamina (v.). 



26. " obtrnsnm, male, left genital hamule. 



dorsal view, 

 lateral view, 

 dorsal view, 

 lateral view, 

 dorsal view. 



lateral view. 



lateral view 



lateral view. 



abdomen from 



