AXDRICUS GLANDUL.E. 61 



Colours. — Pale green, green, pale brown. 



Average dimensions of a mature specimen. — Height, 

 6 mm. ; girth (at base), 12 mm. 



May be sought during the months of July to September. 



Growth is complete by the end of September. 



The typical condition of the gall is bilocular, but unilarval. 



The larva pupates in the gall. The imago emerges dui-ing the 

 following spring. 



Inquiline, No. 136. 



This dainty little gall may be easily distinguished 

 from all other British oak galls by the profusion of 

 long white, silky, and glossy recurved hairs with 

 which it is almost covered, the exposed portion being 

 the papilla. 



It develops from an axillary bud on young twigs ; 

 very rarely on wood of more than two years' 

 growth. 



As soon as it bursts from the bud it is distinctly 

 noticeable owing to the silky-whiteness of the long 

 hairs which are arranged like thatching (without the 

 rods and spars), on a circular hay-stack or wheat- 

 stack, the little papilla standing erect in the centre, 

 hence the English name of "thatched gall" which I 

 propose for it. 



As growth proceeds the hairs remain adpressed to 

 the gall, the texture of which becomes woody. 



The lower portion of the gall is expanded into a 

 turban-like base having occasionally a number of leaf- 

 scales adherent beneath it; these ultimately fall off and 

 expose a somewhat stout process or peduncle by which 

 the gall is held to the twig. In some examples this 

 basal portion is much more fully developed than in 

 others. 



The shape of the gall wdien mature is that of a 

 truncated cone, bearing upon its summit a very small 

 mastoid growth, known as the papilla, wdiich is subject 

 to much variation in size. It is a pale greenish-yellow 

 colour and is destitute of hairs in all stages of its 

 development. 



During the winter the gall falls to the ground, or it 



