348 BRITISH SPECIES [CH. 



Family AGRIONIDAE (Characters, p. 277). 

 Subfamily Platycneminae (Characters, p. 279). 



Genus XV. Platycnemis Charpentier (fig. 145). Quad, rectangular elon- 

 gated. Tibia 23 dilated especially in <J (fig. 9 B). 



31. P. pennipes Pallas. abd 27 28, hw 20 21, pt 0-8, rhomboidal, 

 brown. Thorax black with green dorsal lines. Abd. blue with black markings ; 

 apps. very short. $ abd 2630, hw 20 25, pt 1. Abd. stouter, blue replaced 

 by greenish-yellow. Local; Southern. May Sept. 



Subfamily Agrioninae (Characters, p. 279). 



Tribe Agrionini (Characters, p. 280). 



Genus XVI. Ischnura Charpentier (fig. 18 j). Quad, with sharply acute 

 distal angle. M 2 arises 4 cells distad from nodus in fw, 3 in hw. Pt in fw of <$ 

 bicolorous, proximally black, distally white. Postocular spots present. End of 

 seg. 10 in projecting upwards ; ? with a ventral spine under seg. 8. Colora- 

 tion greenish-black, slightly metallic ; a little blue on <$. Dimorphic females. 



32. /. elegans Vanderlinden. ^ abd 22 26,hwl3 17,^0-6. Postocular 

 spots, thoracic bands and abd. seg. 8 bright blue, 9 10 black. $ abd 22 26, 

 hw 15 20, pt 0-8, unicolorous. Normal form of $ closely resembles <J, but 

 abd. stouter. Heteromorphic form has head, thorax, legs and abd. 1 2 orange, 

 with black markings. Very common. May Sept. 



33. /. pumilio Charpentier. <$ abd 18 24, hw 12 17, pt 0-5. Resembles 

 No. 32, but abd. 8 blackish, 910 pale blue. $ hw 1319. Normal form of 

 $ has blue replaced by yellowish-green on head and thorax ; abd. fairly stout, 

 greenish-black. Heteromorphic form (var. aurantiaca) has head, thorax, legs, 

 abd. 1 2 and part of 3 orange. Rare ; Southern. June Sept. 



Genus XVII. Agrion Fabricius (fig. 148). Quad, with sharply acute 

 distal angle. M 2 arises 5 6 cells distad from nodus in fw, 4 5 in hw. Pt 

 unicolorous. Postocular spots present. <$ with abd. seg. 10 not upturned. 

 2 with a ventral spine under seg. 8. Colours bronze- black and bright blue. 



34. A. armatum Charpentier. abd 29 32, hw 16 19,^0-6. Abd. 1 3 

 as in fig. 179, a. App. inf. large, longer than seg. 10. ? abd 27 32, hw 18 21, 

 pt 0-6. Abd. stouter, blue colour less bright, or greenish ; seg. 2 with black 

 mark pointed basally. Very rare; Norfolk Broads. May June. 



35. A. pulchellum Vanderlinden. <J abd 2332, hw 1620, pt 0-6. 

 Very slender build. Abd. 1 3 as in fig. 179,6. App. inf. small. ? abd 25 29, 

 hw 18 22, pt 0-6; head and thorax with blue replaced by greenish; abd. a 

 little stouter; seg. 2 with apical two-thirds or more black, the black mark 

 concave or three-pointed basally. Local. Apr. Sept. 



36. A.hastulatum Charpentier. <$ abd 28 34, hwll 20,^0-7. Slender 

 build. Abd. 13 as in fig. 179, c. App. inf. small. $ abd 2932, hw IS 22, 

 pt 0-7; abd. stouter, the blue replaced by greenish; seg. 2 with black mark 

 along the whole length. Very rare; Inverness-shire. June Aug. 



