278 THE CANADIAN ENTOMOLOGIST 



form, grasping the mesostigmal laminal or not. The fe- 

 male, by drawing the hind lobe of the pronotum closely 

 against the mesostigmal laminal, prevents the escape of the 

 male. 



D. Dorsum of apex of segm.ent 10 of male modified to 

 form a brace against the middorsal carina or its fork 

 or the cavity in the fork. Anomalagrion, Ischnura, 

 Enallagma. 



DD. Dorsum of apex of segment 10 of male with a viscid 

 pruinose tubercle on either side which attaches itself to 

 the mesoepisternum of the female on either side of the 

 fork of the middorsal carina, the tubercle which cor- 

 responds to the inferior appendage of Anisoptera en- 

 gaging the cavity in the fork between the mesostigmal 

 laminae. Argia {putrida and apicalis).'' 



In my specimens the inferior appendages of the male were in 

 contact with the dorsum of the pronotum of the female in the 

 position shown in fig. 1. The posterior prominence of the inferior 

 appendages fits into the depression between the middle and hind 

 lobes of the pronotum, which is deepened on each side to receive it 

 (figs. 3 and 4). Thus the posterior surface of the inferior appen- 

 dages (p. i. ap.) is applied to the anterior surface of the hind lobe 

 of the pronotum of the female and the postero-ventral surface of 

 the appendages (v. i. ap.) rests upon the postero-dorsal surface of 

 the middle lobe of the pronotum. The upper and outer angle of 

 each inferior appendage bears a small slightly hooked process (n), 

 which clasps the posterior margin of the hind lobe of the pronotum. 

 The superior appendages do not "rest in caps form.ed by depres- 

 sions in the m.esostigmal lamina\ etc." but the reverse is the case. 

 The "car" of each m.esostigmal lamina is received into the conca-' 

 vity of the corresponding male superior appendage (figs. 1 and 4), 

 which apparently rests in the pit on the mesoepisternum just be- 

 neath the former. The mesoepisternal tubercles of the female, 

 which are but slightly developed in this species, do not seem to 

 play an important part in this process, except perhaps in forming 

 the outer boundary of the pit just referred to. I have not actually 



