126 
MISS STAVELEY ON THE NEURATION 
very decept 
accuracy. 
each observation had, therefore, to be repeated manv times to ensure 
The sketches accompanying this paper were (with the exception of two or three which were 
traced from the wings themselves) made with the camera lucida, aided by the compound 
microscope or a simple lens ; and this may excuse any artistic defects that they exhibit. 
The hooks on the front margin of the hind wings of the Hymenoptera may be divided into 
two groups: those placed near the middle of the front edge, which maybe called the 
Distal hooks, and which appear to occur in the wings of all Hymenopterous insects ; and 
those situated nearer to the base of the wing, which have been called the Sub-basal hooks. 
When the latter are present, they are in general quite distinct from the distal series ; but 
in some few insects the two series seem gradually to pass into each other*. 
The disposition, form, and number of these hooks appear to afford, not only good 
characters for the separation of very nearly allied species, such as the species of the genus 
Ophion, but to afford also excellent characters for the distinction of genera and families ; 
and I have little doubt that when more attention shall have been paid to them, their 
importance in the economy of the animals will be fully established. 
Mr. Frederick Smith, in the notice before referred to, expressed his belief that the hooks 
would-be found to be more developed in those insects which have the quickest flight ; but 
further examination has not confirmed this opinion, as one or two of the insects marked 
by him as of very quick flight (as Astata Boops) have the hooks slightly developed and 
few in number. 
The neuration of the hind wings is somewhat similar to that of the fore wings, and 
presents variations which fall naturally into three groups, according to the form of the 
front or costal nerve. 
I. Costal nerve divided 
the base 
A. Upper branch of the costal nerve marginal at least to the centre of the wing, where 
the upper and lower divisions are re-joined. 
Vespid^e. 
maculata 
Polistes (4 species), fig. 43 
Polybia, fig. 44 . . . . 
Eumenid^e. 
Eumenes 
Synagris 
Costal nerve branching at the re-junction. 
Distal hooks commencing on the re-junction 
Mr. Westwood in his 'Modern 
Another character of the order (Hymenoptera) consists in the connexion, during flight, of the two wings on each 
tl V T ^ meaDS ° f a SCrieS ° f mhlUte h °° kS ' al0Dg the anterior mar S in ofthe Posterior wings, which catch 
e hinder margin of the anterior wings, thus producing one continuous surface on each side." (Vol. ii. pp. 76, 77.) 
of * W r^ SCnt mC Ae f ° Uowin S observations :_«< I do not find that Mr. Westwood anywhere makes use 
tne hooks m the classification of the insects ; and in Curtis's ' British Entomology,' where the wings of the different 
genera are often figured in nnnsirlpraWo ,Uf„;i t ^ *.*_■!. , . . ... T 6 .. 
noticed, 
distinguish 
instance 
Walker if he had ever made use of the hooks on the wings 
,, u -, ,, , 6 species OI inese mse <*s> or if he could refer me to any author who had done so ; 
nd he said he had not himself, and, after searching in several works where he thought thev might have been so used, 
he was not able to refer me to ftnv." 5 3 5 
