22 Observations on Cynipidae. 



Each bears in its centre a little conical projection from 

 which ra3^s run out to the margin of the gall. (Fig. 3'^^.) 



The flies emerge in June, and are very easily reared 

 if the galls are collected shortly before they mature. 



Fly. Size, 2 mm. ; black ; thorax shining ; legs 

 yellowish, coxae and bases of femora dark. Male and 

 female similar. 



Experimental breeding. As it is very difficult to 

 collect the flies of this species in large quantity, I have 

 only once been able to make an experiment in breeding, 

 and that was in the open air. On June 20, 1875, 

 I observ^ed several females creeping about on the 

 under surface of the oak leaves and laying their eggs. 

 I marked eight leaves which had been pricked, by tying 

 threads upon them. After three or four weeks small 

 round galls appeared which proved to be those of 

 Neuroterus numismatis. 



[The blister- gall occurs in May on Querais sessiliflora and Q. pedun- 

 ciilata. A different but similar gall appears on Q. puhescens and 

 Q. cerris. 



Inquiline. Sp. ? of Synergns. 



Parasites. Sp. ? of Torynms. This gall continues to live after its 

 gall-maker has emerged.] 



4. Neuroterus fumipennis. Htg.^ 



Gall. Generally circular, with the edges often in- 

 curved and emarginate. The gall is of a pale or reddish 

 colour with delicate brown stellar hairs. (Fig. 4.) 



This gall has a certain resemblance to that of 

 Neuroterus lenticularis, but has more frequently been 



[' Spathegaster varius, Schenck.] 



