io8 British Dragouflic. 



1758). . . . DesCR. Tliorax crassus maculis duabus 

 flavis, ])raeter anticam distinctis nigris lineis, a tergo 

 hirsutis. Abdomen attenuatum ex lato principio. Alee 

 albae, versus basin luteae, sed iiifcriorcs infra luteum 

 colorem nigrre. Abdominis latera et dorsum flavescentia ; 

 Cauda duabus appendiculis teretibus utrinque attenuatis. 

 Nota essentialis, qua ha:;c species ab omnibus distingui- 

 tur, constitit in puncto marginali, quod ut in reliquis 

 versus extremitates nigrum est, sed praster hoc punctum, 

 fusca s. nigra alia macula ad marginem anteriorem, 

 in medio aL-e singular ; adeoque puncta quasi duo 

 marginalia in omni ala. Ocnli postice subtus linea 

 flava. (C. Linnaeus, " Fauna Suecica," p. 371, 1761.) 



Size. 



Length of Male, 39mm. to 47mm. ; expanse of wings, 

 67mm. to 74nim. Length of Female, 41mm. to 47mm.; 

 expanse of wings, 70mm. to 80mm. 



Male Imago. 



Head brown ; face whitish-}-ellow, middle of labium 

 and edge of labrum black ; e\'es brownish. Tliorax 

 brown, with two broad }'eIlow, irregular lateral bands 

 bounded with black ; hair}- dorsal projections, )-ellowish. 

 Lco-s black. ]Vins[s hwaline, tinged with \-ellow towards 

 the base ; between the base and the anal angle of the 

 hind-wings a triangular dark brown j^atch \\ith }-ellow 

 nervurcs ; at the node of all the wings a black spot, 

 from which the insect obtains its specific name ; in 

 general four rows of post-trigonal cells ; about seventeen 

 ante-cubital ncrvures on fore-wings, twehe on hind-wings, 

 about twelve post-cubitals. Pterostigma black, rather 

 narrow, length 4mm. xlceessory menibraue rather small. 



