32 Bulletin Wisconsin Natural History Society. [Vol. 9, Nos. 1-2. 



Taking 25 random males of hageni I find the following : 

 4 specimens with typical Ischnura venation on all wings. 



6 " " both hind wings 1 schnura-f orm. 



7 " " one 



1 " " both fore wings 



2 " " one 



Summarizing': 



All wing's, 4 specimens = lfi wings. 



Both hind wings, 6 " = 12 



One hind wing, 7 " = 7 



Both fore wings, 1 " = 2 " 



One fore wing, 2 " = 2 " 



Total: 39 wings of 100 = 39%, 1 schnura-f orm. 



If it were not for the color and markings and the form of the 

 appendages, some hageni might easily be referred to Ischnura, > 

 especially as the number of postnodals is a variable quantity. But 

 if we correlate the females of Ischnura verticalis, for example, 

 and those of Enallagma hageni with Ischnura venation, we find 

 generic distinctions failing us. This dilemma is aggravated if 

 the females be pruinose or blackened, as most hageni and verti- 

 calis females are. 



The variation or approximation just noted may even exceed 

 the 39% given, especially as the disparity of the number of 

 hageni females to the males, and of vcrticalis males to females, 

 becomes apparent when comparing the figures here listed. These 

 are : 



Enallagma hageni — males 32, females 10. 



Ischnura verticalis — males 28, females 53. 



Using the ratio of 39%, twenty females of /. verticalis would 

 be referred to hageni, the result being 30 and 33 females respec- 

 tively, which seems a much fairer ratio than the listed figures. It 

 would seem, therefore, that a number of the females here listed 

 as /. verticalis are really E. hageni, especially so in view, of the 

 unreliability of the generic character, as cited above. Thus far 

 when collecting I have noted a slight preponderance of Ischnura 

 females over the males, but no excess as the listed figures indicate. 

 (See also E. walkeri, postea). 



