1865.] 331 



Contributions to the Natural History of the CYNIPIDiE of the United States 



and of their Galls. Article 4th. 



BY BARON R. OSTEN SAC KEN. 



I Communicated April 10, 1865.) 



The present paper brings but very few new facts before the entomo- 

 logical reader. The intention which principally prompted me, in pre- 

 paring it was, to give an account of the present state of the European 

 literature on Gynlpldse, (exclusive of Ftgitidse), an account intended 

 especially for the benefit of entomologists unfavorably situated with 

 regard to access to scientific libraries and to whom this literature, 

 scattered over many volumes of transactions of European learned socie- 

 ties would otherwise have remained inaccessible. At the same time, I 

 have taken advantage of this opportunity, in order to correct several 

 errors of my former papers, to complete some descriptions of species 

 and to introduce some remarks, synonymous and others, suggested by 

 the comparison of the specimens of my collection which I owe to the 

 liberality of MM. Walsh and Bassett. In this respect my paper will 

 afford a kind of recapitulation of the N. A. Gyntpldee at present known. 



My correspondence with Dr. Reinhard and the exchange of speci- 

 mens with him, have led me to a somewhat better insight into Har- 

 tig's system of Gynipidse, than T possessed before, but have convinced 

 me at the same time, 1st, that although most of his genera may be 

 easily recognizable to European entomologists, they have never been 

 scientifically defined ; 2nd, that Hartig's system will require a consid- 

 erable development, in order to be applicable to the N. A. Gynipidse ; 

 this development consisting principally in the adoption of several new 

 genera peculiar to North America and coordinate to Hartig's genera 

 Gynlps, Andricus, j\ T euroterus, Spathegaster and Trigonaspis. How- 

 ever, to establish new genera, without strictly defining the already 

 existing ones, would merely increase the confusion. A simultaneous 

 reform of the whole system will therefore be the only warrantable 

 course to pursue. 



About one hundred European gall-producing (psenidous) Gynlpldse 

 are at present known. The number of American species has not quite 

 reached fifty, and yet, considering the great prevalence of oaks in this 

 country, much more abundant in species of this tree than Europe, we 

 may expect that the number of N. A. Gynipidse will far exceed the 



