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XII. Observations on the Neuration of the Hind Wings of Hymenopterous Insects and 
on the Hooks which join the Fore and Hind Wings together in flight. By Miss 
Staveley. Communicated by Dr. John Edward Gray, F.B.S., F.Z.S., V.P.Z.S., 8fc. 
Read June 21st, I860. 
CONSIDERABLE attention has been paid to the distribution of the nerves on the 
fore wings of Hymenopterous insects, and the peculiarities which they offer have been very 
extensively used in the systematic arrangement of these insects, especially in the separation 
of nearly allied genera. 
After many inquiries of the naturalists best acquainted with the subject, I have 
failed to discover that any attention has been given to the distribution of the nerves in the 
lower wings. 
The observations which I have been able to make upon these nerves seem to show that 
they also offer considerable variation, and afford characters which may be valuable for the 
arrangement of the genera and for the distinction of species. 
The existence of a series of hooks on the upper edge of the hind wing, for the purpose 
of uniting the two wings in flight, has been long known, and the hooks were figured and 
described as found in the wing of the Bee, and some other insects of the order, in the 
works of the earlier micrographers ; but I cannot learn that any one has particularly 
studied them, or recorded the peculiarities which they present in different families, or in 
the genera and species of these groups. 
These hooks were generally believed to form a group near the centre of the wing, until 
the existence of some spines or hooks near the base of the wing, in certain species of 
Ichnetimonida?, was pointed out in a note by the writer, inserted by Dr. Gray, of the 
British Museum, in the ' Annals of Natural History' for April 1860. 
The interest taken in those observations by Dr. Gray has induced me to examine further 
into the subject than appears to have been done hitherto ; and, for the purpose of enabling 
me to do so, he requested Mr. Frederick Smith, who has paid particular attention to 
the study of Hymenopterous insects, and who has arranged and described the very exten- 
sive collection of this order in the British Museum (perhaps the most extensive which 
exists), to furnish me with a series of wings of some of the species of the different families 
and genera, for examination. 
These wings were all named by Mr. Smith ; and, in the following observations, I have 
adopted the nomenclature and systematic arrangement used by him in the Museum col- 
lections and catalogues . 
The wings have been mounted in balsam, and now form part of the collection in the 
British Museum : they can therefore be consulted by any persons interested in the subject. 
The observations have all been made with great care from these mounted wings, which, 
although they exhibit much which would not be visible in the wings unprepared, are often 
