THE ENTOMOLOGIST. 



473 



above-mentioned species infers a difference of distance 

 between the surface of the gall and the spot where the 

 purpose of the gall is effected. A Callimome is a nearly 

 invariable attendant on a gall-maker, and with these two 



THYSANUS ATER. 



CIEROSPILUS rACUVIUS. 



alone the annals of the gall are comparatively short and 

 simple, but they are otherwise when Synergi, Eurytomidae, 

 Ormyridae, Pteromalidse, Eupelmidte, Elachistidoe, and 

 Tetrastichidae, are also congregated there, 



Megastignius dorsalis, as it usually comes from the oak- 

 apple, is rather smaller than those from the cherry-gall above 

 mentioned, and the occurrence of the large M. giganteus from 

 the Devonshire gall in England indicates that some Mega- 

 stigmi considered as species may be mere modifications by 

 difference of parasitism. 



z2 



