MATERIALS FOR A FAUNA CANADENSIS. 



451 



as being confined to tropical and sub-tropical climates. Taking the 

 others in order, we give the following analysis of Libellulida, adopting 

 Rambur's sub-families : 



,3 P 03 



' of three pieces 

 or joints 



f scarcely touch- 

 ing, or 

 rate 



to 



« J 



■ widely separat- 

 ed ; sometimes 

 pedicellated 



touching at a 

 point, or a lit- 

 tle separated 



contiguous, to 

 some extent 



, of two joints 



Agrionina, 



Gomphina. 



Aeschnina. 

 Libellulina. 



In characterising the genera, we have not thought it necessary to 

 preserve all Hagen's new genera, but have adopted those of Rambur. 



like a Didymops. 





» M i 



well d i s t i n- 

 guished from 

 the other areo- 

 Ije, its base 

 fermed by a 

 single nervule 



imperfectly dis- 

 tinguished, its 

 base formed by 

 two nervules 



with a protru- 

 sion in the mid- 

 dle posteriorly 



without the pos- 

 terior enlarge- 

 ment, connect- 

 ed in a short 

 space 



swelled 

 grain 



not swelled 

 (body brassy- 

 green) 



Cordulia. 



Libellula. 



Nannophya, 



Genera of Aeschnina. 



Anal angle of the posterior wings of the male rounded oflP ; 

 second abdominal segment of female not auriculated 

 (abdomen with a lateral interrupted carina) Anax. 



Anal angle of the posterior wings of the male acute ; se- 

 cond abdominal segment of the female auriculated ; last 

 segment not spinous beneath Aeschna. 



Last segment of the female spinous beneath, otherwise 



like Aeschna Gynacantha 



Genera of Gomphina. 

 It is only necessary to notice the two following, out of seven genera 

 characterised by Rambur, as being alone likely to aflFord any species 

 to the Canadian naturalist : 



