98 THE ENTOMOLOGIST. . 



The blunt point of the cone by which it is attached to the 

 twig is somewhat flattened ; the base of the cone, viz. the 

 upper end of the gall, forms an almost circular, flat disk, in 

 the centre of which there is often found a small excrescence. 

 This disk is one centimetre in diameter, and has a well- 

 defined border, often quite sharp ; on this border there are 

 generally several projections pointing outwards, and termi- 

 nating in a sharpish point. At first the gall is green, but later 

 turns to a yellowish brown. In the section beneath the disk 

 there is a large, spherical inner gall, coarsely striated, thick- 

 walled, and hard, which touches the moderately hard gall- 

 substance on all sides, but is not joined to it. If that part of 

 the gall near the twig (just below the inner gall) contains 

 parasitic larvae, then the gall assumes a cylindrical shape, as 

 the parasites occasion a swelling in the lower part of the gall. 

 In most cases the development of the Cynips larva is not 

 disturbed by the Synergus larva, so that the gall-maker and 

 the parasite may be bred from the same gall, I found the 

 Cynips quite mature in the first half of October, while the 

 gall was still green ; but, according to my observations, it 

 does not emerge till the end of October or the beginning of 

 November. Cynips subterranea, Gir., certainly belongs to 

 this species, as Dr. Giraud tells me that this gall is only a 

 modified form of C. polycera. The specimens which I have 

 received from him differ from C. polycera in their smaller 

 size, and by their being attached to under-ground twigs, or 

 those which are more or less covered with moss or leaves. — 

 G. L. Mayr. 



This remarkable gall was first figured by Malpighi ('Opera 

 Omnia,' i. 123, fig. 50), but was not noticed from his time till 

 Giraud described the insect and gall anew in 1859 (Verb. d. 

 zool.-botan. Ges. ix. 340). Neither this species nor the 

 preceding have occurred in Britain. Synergus melanopus, 

 S. pallicornis, and Ceroptres arator, are its inquilines, all 

 appearing in April and May of the second year. Callimome 

 regius and Megastigmus dorsalis are probably both parasitic 

 on the gall-maker. Dr. Mayr notices the interesting fact 

 that the position of the Synergus does not interfere with 

 the gall-maker : this is contrary to the history of the 

 greater number of galls, as in most cases the inquilines 

 (Synergi) cause the death of the Cynips, either by its 



