EXTERNAL ANATOMY OF INSECTS. 631 



the moths, in the Bombyces L., this is divided into two, and 

 in Cossus labyrinthicus Don. into three areolets : in some 

 butterflies [Lycccna) there is one insulated nervure*, and 

 in others {Hesperia) there are two b ; 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 

 Neuroptera ; and at the base of this Area, in Morpho, is 

 a roundish areolet d . In this Order the externo-medial 

 and interno-medial nervures coalesce into one, and are 

 only represented separately by their first and third 

 branches c . In the Neuroptera Order the general type of 

 neuration is borrowed from the Orthoptera ; but in Os- 

 mylus, Termes, &c, there is an approach to that of Plata 

 in the Homopterous Heniiptera, and in Psocus to others 

 of that section ; in the second of these genera the ner- 

 vures, 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 ,- 

 and I only regret that his labours were directed to so 

 small a portion of the Class Insecta, and in that portion 

 only to a part of the upper wing ; I say only a part, be- 

 cause all those areolets of the posterior part of the wing, 

 in some cases amounting to Jive f , that lie behind his cu- 

 bital cellules, are not employed by him as diagnostics, and 

 are left without a name. By dividing the areolets of the 



a Jones in Linn. Trans, ii. t. viii./. 7. b Ibid.f. 9. 



c Ibid.f. 2, 3,6 — 9. d I wonder Mr. Jones's plan of 



ascertaining the divisions or subgenera of butterflies by the neuration 

 of their wings has never been followed up ; it would I think furnish 

 an easy clue for the exh'ication of the tribes of all the Lepidoptera. 

 I mean as subsidiary to more important characters. 



€ Pi.ate X, Fig. 6. V, m\ f Ibid. Fig. 8. 



