Lib dill la. 109 



white. Abdomen hain', rather elongate, tapering- pos- 

 teriorly, bright brown ; first segment black, 2 to 5 

 with posterior margin black, 6 mostly black, 7 to 10 

 black ; narrow lateral \'ellow spots on segments 3 to 8, 

 on the last two ver\- small. Anal appendages black ; 

 superior long, round ; inferior about half the length of 

 superior, triangular, slightly bifid at the tip. 



Female Imago. 



Closeh' resembling male, but abdomen is shorter and 

 broader ; \-ellow lateral spots larger, and extending to 

 the ninth segment ; elexcnth segment brownish. ^Inal 

 appendages black, fairl}- long, spindle-shaped. 



Immature Colouring. 



When newly disclosed, the insect is of a pale, ding)' 

 )-ellow colour, but in about twent}"-four hours the 

 mature tints are assumed. 



Variation. 



Z. quadrimaeiilata is perhaps the most variable of 

 British Dragonflies. i'l ) In the first place there is a 

 wide range in size. {1) In what must, from Linnaeus' 

 description, be looked upon as the t\'pe, there is a 

 saffron tinge at the base of the wings. This, especially 

 in South of England specimens, is often much developed 

 in size and intensity, till it ma\' extend as a broad 

 band almost the whole length of the wings from base 

 to tip, giving a \"er}' fine appearance to the insect 

 (Plate V). (3) Less often in the neighbourhood of the 

 pterostigma, and sometimes also of the nodal spots, 

 there is a more or less extended blackish-brown suffusion, 



