44 INTRODUCTORY REMARKS. 



ground for distinctions; as for instance, whether 

 they inhabit an insect in its first, second, or third 

 state, or its eggs only ; and again, upon what class 

 they make their attacks. We never think of putting 

 together into one genus those insects that prey 

 upon dead animals, or live in dung, or upon the 

 same plant. This is going back to the old ento- 

 mologists who made Habitat a generic character (g-). 

 Many of the Ichneiimones Minuti are likewise dis- 

 tinguished by another remarkable character, their 

 wings are without veins. They vary much as to 

 the form of their antennas, in some these are ramose; 

 in others filiform ; in others again clavate ; in a few 

 capitate ; and I possess one or two species in which 

 they are curiously ornamented with verticilli of 

 hairs. Whether these might be divided into more 

 than one natural genus I cannot say, as I have not 

 sufficiently studied them to offer any decided 

 opinion upon the subject; with respect to their 

 place in the system, 1 think they ought to follow 

 Cynips, to which they are nearly allied : I mean if 

 that genus continues at the head of the class. As 

 to those which may be considered as genuine 

 Ichneumons, I am not, as yet, sufficiently conver- 

 sant with them to venture any other remark, than 

 that those whose aculeus is not exerted, have the 

 tongue, in such as I have examined, as I observed 

 above, semicylindrical, and the valvules truncate at 

 the apex ; whereas those whose aculeus is exerted. 



{g) Rai. Hist. Ins. App. p. 378. 



are 



