VI 



INTRODUCTION. 



The most extensive genus, and one of the most difficult of the 

 Tenthredinidce is Nematus, of which 373 species, mostly European, 

 are here enumerated. Many of these, however, will probably prove 

 to be identical when the synynomy of the genus is cleared up, a large 

 number having been established by Hartig and Forster on slight or 

 insufficient characters. It should also be noticed that in taking up 

 Klug's species of other groups, Hartig has frequently copied the 

 diagnoses only, even when, apart from Klug's descriptions, the 

 diagnoses are wholly insufficient for their determination. This has 

 sometimes led later writers to regard Klug's species of Alhnttus &c. 

 as uncertain, where, in fact, no ambiguity exists. 



As the present is the first general Catalogue of Tenthredinidce and 

 Siricidce which has appeared, it is possible that a few species 

 described by old authors may have been overlooked. It is believed, 

 however, that such omissions are not numerous. 



Lastly, I have to thank Mr. P. Cameron, of Glasgow, for his 

 kindness in forwarding types of several of his new species of the 

 genus Tenthredopsis for examination. 



W. F. KIltBY. 



British Museum. 

 Juno 1882. 



