PREFACE. 



THE present volume is devoted to the Nematina, 

 possibly the most difficult group in the entire family ; 

 and, as will be seen, it contains the largest genus, 

 namely, Nematus. The number of species recorded 

 compares very favorably with what is known else- 

 where; but I am persuaded that very many species 

 have yet to be discovered in Britain, especially in the 

 North, where they appear to be most numerous 

 Might I therefore express the hope that some of our 

 Entomologists would pay attention to these interesting 

 insects, and thus enable me to describe many addi- 

 tional species in the concluding volume of this work. 

 Especially is it desirable that they be reared from the 

 larvae ; for in Nematus many species are excessively 

 alike in the perfect state, although quite distinct as 

 larvae. Thus, if they be reared from the larvae, not 

 only will our knowledge of their habits be increased, 

 but the specific distinctions will be more clearly 

 defined. I regret that I have not been able to figure 

 more of the larvae, but living as I do in a large city, 

 both the getting and the rearing of the larvae is a work 

 of difficulty. 



