58 CEROPTRES ARATOR. 



however, already pointed out that the relative lengths 

 of the second and third abdominal segments cannot be 

 regarded as a character of prime importance for pur- 

 poses of classification, inasmuch as there are genuine 

 gall-makers, e. g. Xenophanes, which have the second 

 shorter than the third. We therefore follow Hartig, 

 Mayr, and Thomson in retaining Geroptres near the 

 gall-makers and Synergi, with which in other respects 

 it has so many points of agreement. 



Mayr describes in his Monograph only two species, 

 namely, G. curator and G. cerri ; but Hartig described 

 G. clavicomis, G. melanonerus and socialis, forms 

 which the learned Austrian Hymenopterist was un- 

 able to recognise. 



1. Ceroptres arator. 

 PI. XIII, fig. 4, ? ; 4 a, antenna. 



Ceroptres arator, Htg., Germs. Zeits., iii, 343 ; Mayr, Verh. z.-b. 

 Ges. Wien, xxii, 724, 1. 



Black ; the antennas and legs yellow ; the scape and coxse more or less 

 black ; wings hyaline, the nervures testaceous. Head and mesonotum 

 finely punctured, shining, abdomen impunctate, very shining, the base 

 ferrugineous, pilose laterally. The face bears two acute longitudinal 

 keels. 



Length 1 — 2 mm. 



The other European species of Ceroptres (G. cerri) 

 is not likely to occur in this country, being found 

 only in the galls of the Quercus cerris. 



I have only seen specimens from Clydesdale in the 

 galls of Andricus noduli. Billups (Proc. Ent. Soc, 

 1884, 14) records rearing it from the galls of Gynips 

 Kollari. 



Sweden, Germany, Austria. 



