116 DRAGONFLIES [CH. IV 



complex, of female flattened and leaf-like. Abdomen 

 bronzy green in colour. 

 genera Somatocklora, Cordulia, Oxygastra. 



(28) 23. Abdomen not spotted along mid-dorsal line. 



(27) 24. genus Somatochlora. Pterostigma brown. Ventral ap- 



pendage of 10th abdominal segment of $ triangular. 

 2 species : 



(26) 25. S. metallica, Lind. Dorsal appendages of 10th abdominal 

 segment of with one notch on ventral surface. Ab- 

 domen of <J> slightly swollen at 2nd segment, then a 

 little constricted, swelling out again very slightly pos- 

 teriorly, colour metallic green, ^ and $. Length of 

 <$ 52*5 mm., 9 56 mm. Expanse of wings 77 mm., 

 $ 82 mm. [Very rare. Scotland.] 



(25) 26. S. arctica, Zett. Dorsal appendages of 10th abdominal 

 segment of <$ with two or three notches on ventral 

 surface. Abdomen of 9 not swollen nor constricted, 

 but gradually tapering to posterior end. Colour green 

 with coppery-red tinge. Length of ^ and <j? 49 mm. 

 Expanse of wings <$ 67 mm., $ 68 mm. [Rare. Scot- 

 land and Ireland.] 



(24) 27. genus Cordulia. Pterostigma black. Ventral appendage 



of 10th abdominal segment of $ cleft. 

 1 species : C. cenea, Linn. Colour metallic green ; hinder 

 part of thorax orange- brown. Length of <$ 47*5 50 mm., 

 $ 4649 mm. Expanse of wings < 6670 mm., 

 $ 68 mm. 



(23) 28. Abdomen with yellow mid-dorsal longitudinal spots. 



genus Oxygastra. Dorsal appendages of 10th abdominal 

 segment with long spine on ventral surface at base ; 

 ventral appendage slightly notched at apex. 

 1 species : 0. curtisii, Dale. Colour metallic green with 

 yellow dorsal spots. Length of < 53 mm., 9 50 mm. 

 Expanse of wings < 71 mm., $ 74 mm. 



(2) 29. Family B. ^ESCHNID^:. Triangle of fore-wing placed length- 

 wise, parallel with long axis of wing. Sub-families in- 

 cluded are Gomphince, Cordulegasterince, JEschnince. 



