118 H YMENOPTERA. 



which I named from Curtis before I had seen the other 

 descriptions. 



At this i^oint my notes in the E. M. M. voh iv. terminated, 

 for the same reason which lias in all probability deterred 

 others from i3roceeding. The descriptions of the gemis 

 Si/nergus (with which we are next confronted) are not 

 sufficient for the determination of species, small and numer- 

 ous, of uniform black or pitchy hues, seldom relieved with a 

 little red, and offering but slight differences of sculpture. 

 The empirical mode of guessing at them from the galls 

 which they inhabit, though practised successfully in the case 

 of the Linno^an descriptions of Ci/?iips, fails in this genus, 

 since the same Synergus may or may not be found in dif- 

 ferent galls. The only identification which I can regard 

 Avith certainty is that of *S'. incrassatus, Hart., of which I 

 have $ ? , given to me by a correspondent. Mr. Parfitt 

 once sent me specimens which, from the structure of the 

 antennae, appeared to be C.thauma[^to']c€ra, Dalm., An. p. 96, 

 = ? C crassicornis, Curt., B. E. 320, n. 22, = ? Si/nergus 

 Klugii, Hart., Germ. Zeit. ii. 199. Perhaps also S. iiervosus, 

 Hart., ii. 197, erythroneurus, Hart., ii. 198, vulgaris^ Hart., 

 /. c, and socialis. (KoU.) Hart., 413, are British. A species 

 with rugulose thorax and rufous face common in oak-apples 

 might be facialis, Hart., ii. 199, iii. 346, = Diplolepis 

 gallcE urnceformis, Fonsc, Ann. Sci. Nat. 1832, only the 

 face of the ? is not black, as it should be, according to 

 Hartig. A large species from the galls of C. lignicola seems 

 not to be mentioned. Curtis, in Morton's Cycl. of Agric. s. 

 V. Cynips, describes a species as C quercus inferus, *' larger 

 than C. fidi'iceps [Curt., = Allotria'] : bred from Aphides, 

 and at the same time causing globular red excrescences upon 

 oak-leaves," — in which remark we seem to have a confusion 



