27 



II. and III., between IV. and V., and between VI. and I., it 



becomes scarcely traceable. It is also worthy of notice, that the 

 contents of either pair of classes, with the addition of class VII., 

 may be formed into a tolerably perfect chain of genera, indeed 

 with much less appearance of disconnexion than is observable on 

 passing from either pair into the next pair, — a fact which attaches 

 a degree of importance to the number three, on which, perhaps, 

 at a future time, more may be said, — and thus a chain of relation 

 would be established in each instance, leaving four whole classes 

 entirely out of the question; — a chain which would steadily 

 pursue its way, regardless and in open violation of all established 

 laws of analogy, affinity and dichotomy ; laws which I hope ere 

 long to see pining away like Echo, until they also are really what 

 I now fully believe them to be, vox et prceterca nihil. 



Mr. MacLeay found that in his quinary groups one of each 

 five contained genera or species related to other genera or species 

 in each of the other four groups. That I may be thoroughly 

 understood, I will quote the author's own words : — " In almost 

 every group which has been set before the reader, he must have 

 perceived that one of the five minor groups into which it is 

 resolvable, bears a resemblance to all the rest ; or, more strictly 

 speaking, contains types which represent each of the four other 

 groups, together with a type peculiar to itself."* As far as my 

 observation has extended, this is universaFy the case ; and 

 whether the total number of groups be five or seven, I think 

 I am safe in asserting that the only possible way of making 

 these types, thus representing groups, approach such groups, is to 

 place the heterogeneous group in the centre, and the homogeneous 

 groups around it ; taking care that the type peculiar to itself be 

 its very centre, its " heart's core." Such a heterogeneous group, 

 then, is Neuroptera : its characters as given,-}- I believe, perfectly 

 correct ; and can any one say they are sufficient ? Certainly not ; 

 but had I described it thus — Class VII. Neuroptera, central, 

 partaking of the characters of all the others, I think a better 

 character could not have been given. This class contains a type 

 peculiar to itself — the genus Libellula of Linnaeus : a genus so 



* Horae Entoniologicae, p. 518. f See the Table, 



c 2 



