THE CANADIAN ENTOMOLOGIST. 353 



Lateral gills (pi. XXIII, fig. 9) slender, about six times as long 

 as the greatest breadth, which is at about the distal third; apices 

 acute. About six-elevenths of the upper margin is spinulose. 

 Distad of this the margins are almost devoid of setae. Pigmenta- 

 tion confined to the tracheal branches, scattered but not grouped to 

 form blotches. The median gill is absent in the single exuvia I 

 possess. 



Length of body (without gills) 11; outer wing-pad 3.6; gill 

 4.2; hind femur 2.7. 



Caenagrion resolutum Selys. 



I found this species transforming at Prince Albert, Sask., 

 June 24, 1913, and reared both sexes. I also reared a female at 

 Toronto, which emerged on June 1, 1913, and a male from Wilcox 

 Lake, Ont., which transformed on June 1, 1914. The following 

 description was prepared from the exuvia?. 



Nymph. — The nymph resembles that of Ischnura veriicalis 

 very closely but can be distinguished by the shape of the gills, 

 and the lateral appendages of the male, and in the majority of 

 cases by the larger number of mental setae. 



Form moderately slender, being about the same as in 

 /. veriicalis, E. hageni, E. geminatum, etc., but less slender than in 

 E. signatum and E. pollutum. Eyes moderately prominent; pos- 

 terior margins of head broadly rounded, forming where they meet 

 the eyes a very slight emargination ; six or eight spines of various 

 sizes can be seen on the posterior margin from above and a 

 variable, usually larger, number near the margin in ventral view. 

 There is also a series of spinules of very variable number (4-12) 

 along the postero-ventral margin of the eye. Antennae generally 

 6-jointed, the 7th. joint, when present, seldom very distinctly 

 indicated. The second joint is 4 or 4.5 times as long as thick. 



Labium extending back to about midway between the front 

 and middle coxae; mentum subtriangular, the apical breadth about 

 four-fifths of the length, the sides in the proximal two-thirds 

 straight and diverging at an angle of about 45°, in the distal third 

 feebly arcuate and diverging at a somewhat greater angle; median 

 lobe strongly depressed, convexo-obtusangulate ; mental setae 4-6; 

 lateral lobes shaped as in Ischnura and Enallagma, the distal margin 



