84 GENERA o| IIVMKXOPTERA. 



thorax very coarsely transversely wrinkled : parapsidal iiroovos in front 



wanting; (in galls of Qiierctis cenis) 14. "Synophrus Hartig. 



Second abdominal segment not overhanging all the others; face with radi- 

 ating striii': mesothorax transversely wrinkled anteriorly: cly]ious. at 



l«ust laterally, well develojied 8. 



8.— A suture between mesothorax and scutellum ; anterior margin of scutellum, 

 in front of the transverse groove, not thickened and carinate. or very 

 rarely feebly so: posterior margin of mesothorax nu-dially arcuately 

 emarginate. and laterally iiinre or less arcuatily iHolonged or rounded 

 out. each ))ronounced emargination has also an interrupted transverse 

 furrow, arcuately curved ; parapsidal grooves wanting or not distinctly 

 marked; abdomen petiolate ; (in Oak-galls). .,29. Neuroterus Hartig. 

 A more or less distinct ridge on middle of anterior margin of scutellum.. 9. 

 9.— Cheeks with a sharp furrow ; antcnnte distinctly 15-jointc(l, llagellum rather 

 slender, all the joints at least three times as long as thick ; mesothorax 

 jiolished, with sharply defined, entire parai)sidal grooves ; the two foveae 

 at base of scutellum se])arated by a carina; metathorax with two supe- 

 rior parallel ridges, which at the middle of the disc are strongly diver- 

 gent, then angularly bent and converging to the thoracic peduncular 



articulation; fin Oak-galls) 21. -Trig-onaspis Hartig. 



Otherwise formed 10. 



10.— Antenuie with 11 free joints; mesothorax finely wrinkled, iiuuctiired ami 

 hairy (in /'. siilvestri>< O. S. finely alutaceous and shining) ; base of scu- 

 tellum with two sharplj' marked foveie ; metathorax with two parallel 

 ridges ; abdomen sessile, segments 2-3 connate, with a more or less dis- 

 tinct suture; marginal cell entirely closed; claws of posterior tarsi bi- 



dentate ; (Iniiuiline in Kose and Hiibus galls) 9. Periclistus Fijrst. 



Otherwise formed 11. 



11. — Face, occiput, mesothorax and mesopleura; polished, naked and black ; cheeks 

 about half as long as the eyes; antenna; 14-jointed ; prothorax, near 

 middle of anterior margin, with two fovese, the space between these 

 fovese polished and bare; base of scutellum with two sharply defined 

 furrows; metathorax with two parallel, longitudinal ridges; marginal 

 cell not very elongate; claws of po.sterior tafsi entire; (in PotcntUla 



galls) 8. *Xestophanes Fiir-st. 



Otherwise formed VI. 



12.— Cheeks half as long as the eyes; base of scutellum with two sharjily marked 



foveiE (except in Timaspis) ; abdomen sessile 13. 



Cheeks less than half as long as the eyes; marginal cell open and uuiisually 



elongate 1(1. 



13. — Claws of posterior tarsi distinctly or indistincily l)i(i(iitate, in the hitter 

 ca.se the mesothorax sharply, transversely wrinkled and the marginal 



cell entirely closed and short : antenna' with 11 fri'c joints 11. 



Claws of posterior tarsi entire 15. 



It. — Mesothorax prdished or nearly so, with sharply defined parajisidal grooves; 

 fovea- at base of scutellum deei>or moderately dee]) and not transverse; 

 marginal cell ojien at wing-margin, sometimes closed in J), ntdicum : 

 claws of posterior tarsi l>id( mate ; (in galls of Rnbus and Potentilla). 



l.l. Diastrophus Hartig. 



