1908] Dragonflies of the Ottawa District 17 



is a fairly good one, and the species comprising it indicate a great 

 variety of aquatic environment. Species inhabiting the larger 

 lakes and rivers, ponds, sluggish creeks and rapid streams are 

 all represented. 



Of these 47 species 42 range southward throughout Ontario, 

 or have been taken in neighboring parts of the United States at 

 moderate elevations. Seven or eight of these are more common 

 in the upper Austral Zone, and probably do not range far into 

 the Canadian Zone. The remaining five are more or less 

 characteristic of the Boreal Zone. 



The Dragonflies (order Odonata) are readily separable into 

 two large groups or sub-orders, the Zygoptera or Damsel-flies, 

 and the Anisoptera or Dragonflies proper. 



The damsel-flies are mostly small deUcate forms, with a 

 slender abdomen and comparatively feeble powers of flight. 

 They are easily known by the somewhat hammer-shaped head 

 with its wideh^ separated eyes, and by the fact that the two 

 pairs of wings are similar in form, and in repose are held together 

 in the vertical plane or only half spread. 



The Anisoptera, on the other hand, are generally larger 

 and more robust than the Zygoptera ; the hind wings are broader 

 than the fore pair, and are held in the horizontal position. The 

 eyes are commonly larger and closer together frequently touch- 

 ing one another above. 



Sub-order 1. ZYGOPTERA. 



This sub-order contains but one family, the Agrionidag, 

 although Calopteryx and its allies are placed by some authors 

 in a separate family. 



Genus Calopteryx, Leach. 



Comparativelv large species with bright metallic green 

 bodies and broad rounded wings, which, unUke those of our 

 other damsel-flies, are partly or entirely clouded with dark 

 brown or black. They frequent woodland streams, flitting along 

 the banks like butterflies, or chasing each other over the water. 



Two species occur in Ontario, and both have been met 

 with at Ottawa. 



1. Calopteryx maculata (Beauv.), Burm. 



Ottawa, Hull, 3 males, 3 females (Gibson, Letourneau, 

 Harrington, Young). 



Length of body male, 46 mm., female, 52 mm. 



Length of hind wing . . " 32 mm., " 36 mm. 



Width of hind wing.. . " 10 mm., " 10 mm. 



This is the commoner of our two species of Calopteryx, 

 and ranges throughout the southern part of the province and 



