THE CANADIAN ENTOMOLOGIST. 355 



3 mental and 5 lateral setae. In E. czlverti there are four mental 

 and 6, or sometimes 5, lateral setae. Calverti, however, is much 

 larger with very dark gills, and in all the Enallagmas the gills are 

 more or less pigmented. E. geminatum is the most like C. resolu- 

 tion of the species mentioned, but the branches of the tracheae of 

 the gills are less regularly distributed and are distinctly pigmented, 

 and the lateral lobes of the labium have only five lateral setae (as 

 known at present ). In carunculatum the lateral appendages of 

 the male are much like those of resolutum but the spinules of the 

 abdominal segments are 'much coarser (fig. 32, d) 



Ischnura cervula Selys. 



Several nymphs of this species were taken by the writer from 

 the reedy margin of a large pond in the Bow Valley, at Banff, 

 Alta. A female was reared from one of these nymphs at the 

 Biological Station, near Nanaimo, Vancouver Is., emerging on 

 July 20, 1913. 



Form of body identical with that of /. verticalis the only 

 distinctive character being found in the shape and pigmentation 

 of the gills. 



Eyes moderately prominent, posterior margins of head 

 broadly rounded, forming where they meet the eye a very slight 

 emargination. Posterior surface of head with numerous spines, 

 and a series of minute spinules of variable number along the 

 postero-ventral margin of the eye. Antennae 7-jointed, the second 

 joint 4-4.5 times as long as thick. Labium extending back to 

 about midway between the bases of the first and second coxae, 

 sides of mentum almost straight, there being only a very slight 

 increase in the angle of divergence at about the distal three-fifths; 

 breadth at base of lateral lobes about five-sixths of the length; 

 median lobe not very strongly depressed, bluntly obtusangulate; 

 lateral lobes shaped as in /. verticalis, C. resolutum, etc., distal 

 margin with two or three very minute teeth, preceding three much 

 larger ones; end-hook a trifle larger than in verticalis; movable 

 hook half as long as the lateral lobe; mental setae 4 (rarely 5 on 

 one side) ; lateral setae 5 or 6. 



Lateial margins of abdominal segments with a series of very 

 short black spinules, forming several irregular rows. Gills (pi. 



