EXTERNAL ANATOMY OF INSECTS. 629 
Lepidoptera. In this last-named Order there are some 
variations with regard to their neuration—thus, amongst 
the butterflies in Urania, &c., there is -no closed areolet 
in any of the wings, and almost all the nervures diverge 
from the base ?; in Morpho, &c., there is only one in 
the primary wing’; in Heliconius, &c., there is one 
in both wings; amongst the moths, in the Bombyces L., 
this is divided into two, and in Cossus labyrinthicus into 
three areolets : in some butterflies (Lycena) there is one 
insulated nervure°, and in others (Hesperia) there are 
two‘; in these two last, and Heliconia, Urania, &c., the 
end of the Costal Area is divided into several areolets by. 
oblique nervures *, which gives them some analogy to 
the wings of many Neuwroptera ; and at the base of this 
Area, in Morpho, is a roundish areolet‘. In this Order 
the externo-medial and interno-medial nervures coalesce 
into one, and are only represented separately by their 
first and third branches. In the Neuroptera Order 
the general type of neuration is borrowed from the Or- 
thoptera ; but in Osmylus, Termes, &c., there is an ap- 
proach to that of Fata in the Homopterous Hemiptera, 
and in Psocus to others of that section; in the second of 
these genera the nervures, ‘except those of the costal 
margin, are spurious. 
I now come to the Order in which M. Jurine has la- 
boured with so much success, I mean the Hymenoptera ; 
* Jones in Linn. Trans. ii. t. viii. f. 2. > Ibid. f. 5. 
© Ibid. f. 7. a Tid. f. 9. © Ibid. f. 2, 3,6—9. 
£ I wonder Mr. Jones’s plan of ascertaining the divisions or genera 
and subgenera of butterflies by the neuration of their wings has 
never been followed up; it would I think furnish an easy clue for 
the extrication of the tribes of all the Lepidoptera. 1 mean as sub- 
sidiary to more important characters. ® Prate X, Fic. 6.1, m*. 
