12 BKlTiSH OAK GALLS. 



galls, or a series of illustrations, many forms which 

 resemble well-known British specimens ; e. (j. Dryo- 

 cosmus cevrlpMliis on twigs of Q. cerrU^ is very much 

 like Aphilothrix corticis and A. Sieholdi, which do not 

 appear on Q. eerris in Britain; Gjinips cerricola is like 

 Biorliiza aptera ; Andvicns crisjxdor like Spatheijash'T 

 haccanim; Nenroterus i^aUens like N. ostrens ; A. 

 cydouise- like A. inffator ; N. lamigivosus, Gpcidomyia 

 eerris, and G. circinnans all resemble N. lenticular is 

 and N. fumipennis. Of British forms, Andricus cir- 

 cnlaii.s, Spathegaster cdbipes, and 8. verrucosufi are 

 similar in form ; so also are Andricus (jlolmli, A. 

 autnmiialis, A. collaris and A. clementiiide. Further 

 illustrations might be given were it necessary. It is 

 also noteworthy that the positions these galls occupy 

 on the tree are very similar. 



DLSSIMILARriT OF ShAPES. 



(a) Glohiddv = spherical = globulose. — This is a 

 somewhat prevalent form, but subject to variation in 

 which the opposite poles are depressed, such galls as, 

 e. g. Dryophanfa agama and D. divisa being termed 

 oblate. Examples of G. Kollari are not infrequently 

 seen which are as perfectly spherical as though they 

 had been turned on a lathe. Aphilotlivix glohuli is 

 normally true to shape ; denuded of its outer green 

 rind, it is an almost perfect sphere. 



(b) Oroid. = oviform. — This term is applied to those 

 galls whose long axis considerably exceeds that of the 

 short axis. 



Spafhegaster alhlpes typifies this form, although it 

 has a small style at the distal end. 



(c) Beniform. — One gall is kidney-like in outline — 

 that is BiorJiiza renum. Some specimens are very true 

 to form; others, however, approximate an ovoid, and 

 now and again a globular form will be found. N. ostrens 

 occasionally approaches the reniform shape, and when 

 mature, and spots and basal scales are absent, it is 



