DlJYOrHANTA DISTICHA. 



Ill 



seldom will as many as fifteen or twent}^ galls be found 

 on one bush ; but when this does occur the contiguous 

 bushes may be searched in vain for more specimens. 



This gall is verj^ distinctive in appejarance and 

 construction. It is firml}^ attached b}^ a very small 

 pointed portion of its ])ase. The point of attachment 

 does not show on the upper surface of the leaf. It 

 may be found more frequently on oak trees and bushes 

 in woods than on those along hedgerows ; occurring 

 rather sparingly, not many leaves on the same branch 

 being galled, and, seldom more than six or eight 

 specimens on one leaf. 



The interior is bilocular ; a condition caused by the 

 convero-ence of the inner walls to form a thin hori- 



^-^ 



Fig. 12.— Three aspects of the same gall caxised hy Dryophanta disticha. 

 A. Side. B. Top. c. End. All nat. size. Dele, ad nat. E.C. 



zontal division devoid of any opening. The upper 

 cavity is tenantless. The lower cavity is the larval 

 chamber. The imago eats its way out through the 

 base of the structure. 



Exteriorly the gall is glabrous, slightly glossy, and 

 unique in outline. The upper portion is distinctly 

 umbihcated, from the centre of which there arises, in 

 some specimens, a minute papilla. When viewed 

 under a lens, most of the galls are seen to be studded 

 with few, or many, raised l)rown spots. The shape of 

 the gall is sometimes circular, but normally it is 

 longer than broad, the height being about the same as 

 the breadth. 



This species is not mentioned in 'Alternating 

 Generations ' ; and it ajDpears to have escaped the 

 notice of most British gall collectors. 



