120 British Dragonjiics. 



Wings hyaline, with the extreme tip sometimes sh'ghth' 

 clouded, one (or twoj dark brown lines at the base of 

 the fore-wings, and a similar line and a triangular spot 

 at the base of the hind ones ; on these spots the 

 nervures are }'ellowish ; three rows of post-trigonal 

 cells; ante-cubital ner\ures about 12, j^ost-cubital about 

 I I. Pterostigma nearl}' black, rather narrow, about 3mm. 

 in length. Accessory r/cuibrnnc small, rather dark. 

 Abdomen, sides nearh- parallel in segments 2 to 6, the 

 last four tapering ; a distinct dorsal keel ; colour light 

 blue, except segments i and 2, which are dark, and 

 a black mid-dorsal line, which, starting on segment 7, 

 spreads out posteriori}- till it occupies nearl}' the whole 

 of segment 10 ; each of the blue segments has two 

 tiny transverse black streaks, one on each side of the 

 mid-dorsal line in the posterior part of the segment. 

 Anal appendages as long as the ninth segment, black ; 

 upper cylindrical, pointed ; lower triangular, a little 

 shorter, turned U]:) at the tip. 



Female Imago. 



In the female the abdomen is tawn}-, with the black 

 mid-dorsal markings on more of the segments than in 

 the adult male. The wings are tipped with dark brown. 

 The head and thorax are lighter than in the mature 

 male, and of a yellowish-brown colour, like that of the 

 abdomen. 



Immature Colouring. 



Apparent!}' the male of this species is ver}- slow in 

 assuming its cerulean tint ; till then it \-cr}- closel}- 

 resembles the female, which does not change nuich in 



