THE CANADIAN ENTOMOLOGIST 421 



long as inner margin of lobe. Mental setae 11-15 (one specimen 

 has 11 and 14, the other 13 and 15) of which the outer fourth to 

 sixth is the longest. Lateral setae 11 (10 on one side of one speci- 

 men). Abdomen ovate, broadest at seg. 6, tapering almost equally 

 roxi mad and distad, the lateral margins almost regularly arcuate, 

 fringed with spinules which become gradually stronger caudad. 

 Lateral spines of seg. 8 about two-fifths as long as the margin of 

 the segment, their outer edges continuing the regular curve of the 

 abdominal margin, their general direction slightly convergent; 

 those of seg. 9 about three-fifths as long as the margin of the seg- 

 ment, extending back to the apices of the lateral appendages, their 

 outer margins straight and about in line with those of the segment, 

 their general direction somewhat convergent. Superior appendage 

 keeled above in the distal half, basal breadth about three-fourths 

 the length, apex slender, slightly acuminate, sharp-pointed; lateral 

 appendages about half as long as the superior; inferior appendages 

 slightly surpassing the superior, with 4 or 5 spinules on their outer 

 margins. 



Colour pattern. — The two exuviae show nothing distinctive 

 in coloration. They are pale with darker mottlings as in glacialis 

 and intacta. Femora with sub-basal and anteapical annuli and 

 darkened at apices, tibiae with basal and median annuli, also dark- 

 ened at apices. Abdominal segments with a row of pale spots on 

 each side, nearly midway between the middle line and the lateral 

 margins. These spots are surrounded by darker cloudings and 

 behind each is a dark spot. They are obsolescent in front of seg. 6. 

 Laterad of these are irregular dark annuli with pale centres, and 

 at the lateral margins of most of the segments the darker colour 

 occupies the anterior half of the segment. Lateral spines pale, 

 tipped with dark brown. 



Length of body 19-20 mm.; outer wing-pad 6 mm.; hind 

 femora 5.8-6.0 mm. ; width of head 5 mm. ; width of abdomen 7 mm. 



Explanation of Plates xii and xiii. 



Plate XII — Nymphs of Leucorrhinia, left lateral views of 

 abdomen. 



Fig. 1. — L. frigida. Fig. 3. — L. glacialis. 



Fig. 2. — L. intacta. Fig. 4. — L. proxima. 



