1S99.] GROTE — SPECIALIZATIONS OF LEPIDOPTEROUS WING. 43 



have, however, vanished. No concession to this fact is made by 

 placing the Papilionides, as Prof. Comstock does, between the 

 Blues and Skippers, clearly, even if distantly, related groups, offer- 

 ing at least no such contradictory characters as do the Swallowtails. 

 Prof. Comstock in his able treatise, to which I am much indebted, 

 does not entertain the view that the Papilionides may not have 

 branched off from the immediate stem of the other butterflies, nor 

 does he apparently insist upon the morphological value of vein 



The diphylism of the diurnals is founded by me on the following 

 characters : 



A. Butterflies having a short anal vein on primaries, running from 



base to internal margin ; on secondaries only one internal 

 vein Papilionides. 



B. Butterflies wanting the anal vein on primaries, instead vein vii 



is forked at base (viii), this fork sometimes wanting through 

 degeneration, and having more than one internal vein on 

 secondaries Hesperiades. 



All the Hesperiades examined by me have two internal veins to 

 the hind wings, except PseudopoJitia^ which has three. This 

 peculiar butterfly has the radius strongly specialized, and the reten- 

 tion of the third internal vein may have been necessitated by the 

 circular shape of the wings. , Theoretically it may be considered 

 that all the diurnals possessed primitively three internal veins, in 

 addition to the fold (vi), of which the Hesperiades, with the excep- 

 tion above noted, have parted Avith one, the Papilionides with two 

 veins. In this particular the latter group are more specialized than 

 all the other butterflies. The Saturniadae, among the higher 

 moths, have reached the same grade of specialization in this par- 

 ticular with the Papilionides. A diminution in the number of 

 internal veins characterizes also certain of the more specialized 

 groups of the Bombycides. The monotypic character of the Papi- 

 lionides is evinced by the possession of vein *' ix " of primaries, in 

 which they appear to diff"er from all other butterflies, not by the 

 number of internal veins, or by any other characters which they 

 can be shown to share with other lepidoptera. Throughout my 

 writings I have tried to show the direction of the evolution taken 

 by the neuration, and I have accounted for the principal changes 

 in position of the veins by their following these directions in spe- 



