234 Linnean Society. [March 18, 



made by Jones, by M. Boisduval, and by M. Lefevre to apply the 

 characters drawn from the neuration of the wings to the arrangement 

 of Lepidoptera ; and to the use of characters derived from the same 

 source in the works of M. de Haan, Dr. Rambuhr, and Mr. West- 

 wood. In the present paper he endeavours to test the value of the 

 neuration of the wings in subdividing a large natural group, for which 

 purpose he selects the genus Argynnis of the ' Encyclopedic Metho- 

 dique.' 



After stating generally the theory of the wing proposed by M. 

 Lefevre, Mr. Doubleday proposes an amended theory as follows : 

 " That the structure of the wings in insects is to have two distinct 

 sets of air-vessels or nervures, three belonging to the anterior half of 

 the wing, three to the posterior ; that in those species in which the 

 wings are in the most truly normal condition these nervures are all 

 fuUy developed and all subserve to their true functions ; that in de- 

 scending from these we first find some of the nervures less developed, 

 but still subserving to their functions, then becoming gradually atro- 

 phied, and at last disappearing altogether ; and that this gradation de- 

 pends partly on the rank which the species hold in the true system of 

 nature, and partly on their oeconomy ." The three upper nervures exist, 

 Mr. Doubleday states, in the anterior wings of a large portion of the 

 Heterocera ; but the lowest or discoidal one is often wanting, though 

 its nervules remain : in the Rhopalocera it is always wanting, and its 

 nervules are united either to the subcostal or median nervures. 



Admitting the correctness of the above views, we have in the 

 Rhopalocera a median nervure with constantly three nervules, above 

 which are the two discoidal nervules, and then the subcostal nervure, 

 generally offering five nervules, but sometimes only three. Various 

 modifications in the number and connexion of these nervules are in- 

 dicated in different genera. 



The genus Argynnis, Godart, always offers five subcostal nervules, 

 never, as Mr. Doubleday believes, anastomosing with the costal ner- 

 vure. Removing from it three species, Arg. Alcandra, Aceste and 

 Lucina, and perhaps Arg. Metea, and adding to it some of the Ce- 

 thosice, it becomes a most natural group. Of the subdivisions pre- 

 viously made in it Mr. Doubleday takes a brief review, and then pro- 

 ceeds to point out the sections into which he proposes to divide it, 

 which are founded in a great degree on the position of the subcostal 

 nervules. 



The first of these is Agraulis properly so called ; the second com- 

 prehends Argynnis Thais, Clagia and their allies ; Arg. lole forms 

 the type of a third ; the fourth is formed by the genus Phalanta of 



