22 The Ottawa Naturalist. [April 



The red colour of this little species serves to distinguish 

 it at once from all other members of the Zygoptera in our fauna, 

 except perhaps the orange female of Ischniira verticalis, from 

 which it differs in the alisence of the two round spots on the 

 back of the head, the reduction of the black markings of the 

 abdomen (Seg. 1-5 in the male entirely red), and the uniform 

 colour of the dorsum of the thorax, which is dull black in the 

 male, reddish-brown in the female (striped in verticalis). 



This species occurs throughout the United vStates, and in 

 Canada has been reported from Quebec. Ontario, and British 

 Columbia. 



Genus Exallagma, Charpentier. 



To this genus belong the familiar little black-banded blue 

 • species that are so abundant about ponds and streams through- 

 out the summer. The males of most species are readily separated 

 by the form of the abdominal appendages, but the females are 

 often impossible to determine with cei'tainty. Their coloration 

 is usually very different from that of the male, greenish or 

 reddish yellow being the prevailing ground color of our species. 



Enallagma is separated from Ischnura bv the following 

 venational characters. (See Fig. A). In the former the nodal 

 sector arises near the fifth postcubital in the front wings and 

 near tiie fourth in the hind wings; in Ischnura it arises near 

 the fourth postcubital in the front wings and near the third 

 in the hind wings. 



12. Exallag.ma Hagexi (Walsh), Selys. Fig. G. 

 Ottawa, July 23rd, 1907, 1 male (Gibson). 



It is rather surprising to find but one specimen of this 

 abundant species in the collection, although some of the females 

 placed under E. ebriiim may belong here. It is our most common 

 and generally distributed Enallagma. 



Apart from the differences in the abdominal appendages 

 of the male, this insect approaches the next verv closely. 



13. Enallagma ebrium Hagen. Fig. H. 



Ottawa, 17 males, 19 females (some of the females may 

 belong to E. Hageni); June 7th, 17th, 1899, 2 males; June 3rd, 

 1903, 1 female (Gibson); July 7th to 23rd, 1907, 7 males, 7 

 females ; August 1st, 1907, 4 males. 1 female (Gibson, Letourn- 

 eau) ; 3 males, 10 females (Fletcher, Tavlor) ; Kettle Island, 

 Ottawa R., July 2nd, 1906, 1 male (Gibson). 



This is apparently the common Enallagma at Ottawa, 

 and although an abundant species in many parts of Ontario, 

 it seems to be more local than E. Hageni, and probably does not 

 range so far north. 



