158 British Dragonflies. 



alongt^es . . . elle a plus de deux pouces et demi de 

 long. (P. A. Latreille, " Histoire Naturelle des Crustaces 

 et des Insectes," torn, xiii., p. 6, 1805.) 



[Kirl)y, in his " Synonymic Catalogue," makes Cordulegaster 

 feminine, while most authors make it masculine. As the generic 

 name is really adjectival, agreeing with the idea of a genus, it 

 may be of any gender suitable to the form of the word. Cordiile. 

 i^astcr may, therefore, grammatically be either masculine or feminine, 

 and. as it has generally been used as masculine, it seems better to 

 let it continue to be so used.] 



Size. 



Length of Male, about 75mm. ; expanse of wings, 

 92mm. Length of Female, including ovipositor, 84mm. 

 to 86mm. ; expanse of wings, loomm. to 103mm. 



Male Imago. 



Head hair\- ; frons yellow, with a central black streak 

 in front, and a black line behind along the vertex ; nasus 

 yellow, except the centre of the lower edge, which is 

 black ; labrum yellow, with black margin ; gena; yellow 

 basally ; labium yellow. Vertex black ; ocelli distinct. 

 Eves rather small, green, just meeting at a point ; yellow 

 triangular spot behind eyes. Protliorax black, bordered in 

 front and behind with )'ellow, the hinder yellow line 

 interrupted in middle. Thorax hair\-, black ; two brcmd 

 yellow bands in front, and two others, also broad, on 

 each side, with a narrow one and a spot between ; at 

 the base of the costa of each wing a small }-ellow sijot ; 

 between the fore-wings a large one ; and between the 

 hind-wings two large adjacent ones. Wings long and 

 narrow ; costal margin golden ; anal angle of hind-wings 

 produced into a blunt point. Ptcrostigma narrow, black ; 

 of fore-wings 4mm., of hind-wings 5mm. Accessory 



