52 BRITISH OAK GALLS. 



apex, which is bhintly pointed or sometimes mam- 

 milated. It is hard and woodj, with very thin walls 

 which form a large larval cavity without an inner gall. 

 The exterior is covered with short, simple, yellowish 

 hairs, most of which fall away when the gall is past 

 maturity and the surface becomes rough. 



" The gall is very similar to that of pilosas, hut 

 generally the latter may be known by being somewhat 

 larger, not so globular, stouter, and not tapering so 

 much at the ajDex, as a rule, nearly as broad as at the 

 base; the hair is longer " ('Brit. Phyto. Hymen.,' vol. 

 iv, p. 94). 



On account of their very small size these galls easily 

 escape observation, but their presence may often be 

 detected if catkins with bent and thickened stalks are 

 carefully examined with the aid of a pocket lens. 



The imago is very small, about 1*7 mm. long; yellow, 

 and orange in colour ; wings hyaline. It eats its way 

 out of the gall during the latter 23art of June or quite 

 early in July. 



The galls do not fall, and often remain, together 

 with the stalk, on the tree throughout the summer. 



Andricus circulans, Mayr. 

 (Plate V, div. C.) 



Andricus circulans, Cameron. Fitcli, Mosley. 



English name of gall. — " The Turkey Oak Bud Gall." 



Position of gall. — In axillary buds of Q. cerris. 



Manner of growth. — Glabrous, glossy, gregarious, con- 

 glomerated. 



Colours. — Yellowisli-brown, red, reddish-brown. 



Average dimensions of a mature specimen. — Height, 

 4 mm. ; breadth, 1'5 mm. ; girth, 4'5 mm. 



May be sought during any month of the year. 



Growth is complete by the end of August. 



The typical condition of the gall is unilocular and imilarval. 



The larva pupates in the gall. The imago emerges during May. 



Parasite, No. 18. 



Alternate agamous generation (according to Beyerinck), 

 Cynijjs KoUari, Hartig. 



