78 



HARDWICKE'S SCIENCE-GOSSIP. 



CHAPTERS ON BRITISH DRAGON-FLIES. 



No. III. 



By E. B. Kemp-Welch. 



Second Group. 



Fore and hind wings alike in shape. 



First division. — Anteciihital ncrvures iinincrous. 



Calopterygid.-e. 



Genus Caloptcryx (Leach). 



/"" VIRGO {lAxm.). Male, wings broad, deep blue, 

 ^ * the reticulation very fine ; head, thorax, and 

 abdomen, deep metallic blue ; no pterostigma trace- 

 able. Female, wings brown, but clear ; pterostigma 

 clear, placed comparatively far from tip of wing ; 

 thorax and abdomen metallic green or copper. 

 British Islands generally. Length 17 lin. ; exp. 21 lin. 



C. spkndens (Harris). Male, wings more narrow, 

 deep blue, or black in the centre only, the base and 

 tips being clear, and the reticulation not so close 

 as in C. virgo ; no pterostigma ; colour as above. 

 Female as that of C. virgo, but the pterostigma 

 more nearly apical. British Islands generally. Length 

 17 lin. ; exp. 21 lin. 



It is noteworthy, that although these two species 

 are about equally common, they seldom or never 

 occur together in the same locality. 



Second division, — Two aniccuhital ncrvures, 

 Agrionid.^. 



(^The wings of this family, being iiiiiforniJy clear and 



hyaline, will not need to he described.) 



A. Tibiic dilated. 



Genus Plafycncniis (Charp,). 



P. pennipes (Pall.). Male blue or whitish ; a black 

 band across the head between the eyes ; two longi- 

 tudinal bands, and two lateral lines (black) on 

 thorax ; an interrupted double black line down the 

 abdomen, or two black dots on the hinder end of 

 each segment ; pterostigma clear. Female green, 

 with yellow thorax ; markings otherwise the same ; 

 pterostigma ochreous. In both sexes the tibise of the 

 middle and hind legs dilated. England and Scotland. 

 Lengtii 12 lin. ; exp. 16 lin. 



E. Tibicc cylindrical. 



a. Pterostigma large, oblong. 



Genus Lestes (Leach). 



t Back 0/ head bronzed. 



L. viridis (Van der Lind.). Bronze-green ; thorax 

 with three narrow yellow lines in front ; joints of 

 abdominal segments marked with yellow ; pterostigma 

 large, pale light red ; upper anal appendages of male 

 like pincers, with a basal tooth, and toothed towards 



the ends. Doubtfully British. Length 15 lin. ; 

 exp. 18 lin. 



L. nympha (Selys). Metallic green, powdered with 

 blue (S), stout, of variable size ; pterostigma smaller, 

 black ; upper anal appendages like pincers, with two 

 pointed teeth, internally rather far apart ; the lower 

 ones long, dilated at the end. England, Ireland. 

 Length 12 lin. ; exp. 14 lin. 



Z. sponsa (Hans.). ]\Ietallic green, tinted with 

 blue in the 6, and coppery reflections in the j ; 

 pterostigma not very large, black ; upper anal 

 appendages pincer-like, with two internal teeth, 

 nearer together ; the lower ones not dilated at 

 the end. England. Length 12 lin. ; exp. 14 lin. 



\\ Back of Iiead yelloio. 



L. vircns (Charp.). Metallic green ; more slender 

 than the preceding ; pterostigma reddish (Hagen), 

 black (Charp. Lib. Eur. pi. 34) ; thorax underneath 

 with three black spots on each side ; upper anal 

 appendages pincer-like, with a small basal tooth, 

 and dilated a little in the middle internally ; the 

 lower short, converging at the end, which is rounded 

 and hairy. England, local ; New Forest. Length 

 12 lin. ; exp. 14 lin. 



L. barbara (Fabr.). Metallic green, stout ; ptero- 

 stigma, one half dark, the outer half yellow ; thorax 

 without spots underneath ; upper anal appendages 

 pincer-like, with a small tooth at the base, and 

 slightly swelled at the middle inside ; the lower 

 short, ends slender and diverging. Ireland ? (one 

 specimen in Dublin Museum. Hagen.) Length 

 12 lin. ; exp. 17 lin. 



b. Pterostigma small, rhomboidal. 



Genus Agrion (Fabr.). 



t Head without spots behind the eyes. 



A. najas (Hansem). Dark bronze-green, light 

 underneath ; pterostigma darkest in the centre ; thorax 

 unmarked, or with a narrow yellow line at each side ; 

 abdomen ( ^ ) tipped with blue on the two last 

 segments ; anal appendages of male leaf-shaped, 

 turned outwards. England and Ireland. Length 

 13 lin. ; exp. 18 lin, 



A. minium (Harris). Deep red; pterostigma dark ; 

 thorax dark bronze, with a lateral stripe, red or 

 yellow, on each side ; legs black : abdomen has the 

 segments towards the apex banded with dark bronze ; 

 anal appendages of the male long, rather curved ; 

 the lower bifid at the tip. British islands generally. 

 Length 13 lin. ; exp. 17 lin. 



A. tenellum (Villers). Red ; thorax dark bronze, 

 without markings ; legs red ; anal appendages of 

 male very short ; the upper with a truncate tubercle ; 

 the lower simple. Local in the south of England. 

 Length 12 lin. ; exp. 14 lin. 



