1899.1 GROTE — SPECIALIZATIONS OF LEPIDOPTEROUS WIXG. 9 



branch of the media, vein iv..„ becomes cubital ; whereas in the 

 Pieridae it becomes radial, as in the Hesperiades generally, with 

 the exception of Leptidia, an aberrant pierine form in which this 

 branch also becomes cubital on the hind wings. In the Lycaenidai- 

 Hesperiadoe it remains central, while it becomes radial in the 

 Nemeobiidae, as in the Pieri-Nymphalid?e. The upper branch of 

 the media, vein ivj, ascends the radius in the specialized forms of 

 the Papilionides, as in the Pieridse, and does not remain perma- 

 nently attached to the cross-vein, from the upper corner of the 

 cell, as in the Nymphalids. 



The second direction in which specialization shows itself lies in 

 the suppression of the branches of the radius on the fore wings. 

 The five-branched radius, exhibited in a generalized state in the 

 Papilionidae, becomes four-branched in the most specialized butter- 

 flies of the group I have yet examined, in Farnassiiis apollo and 

 its very close ally, Doritis m7iemosyne. 



For the rest, the specializations of the neuration generally show 

 themselves in absorption, so that I have laid it down as a principle 

 that the amount of the specialization is measured by the extent of 

 the absorption or disintegration. 



The so-called "tails" to the hind wings in this group are pro- 

 longations of vein ivg. They are probably to be regarded as 

 characters of specialization, and they possibly had their origin as 

 secondary sexual ornaments of the male sex, although now most 

 of the females have followed suit. In certain Papilios in which 

 the female is mimetic, the " tail " in this sex may have been aban- 

 doned after having been originally acquired. 



Nomenclature and Homology of the Veins. 



The ancestors of the Papilionides must have exhibited vein ix of 

 the primaries, since this is evidently a retained and not an ac- 

 quired character. I follow Comstock in numbering the loop at 

 the base of vii as viii in the Hesperiades and other groups. This 

 vein viii is absent in the Papilionides, where there is no place for 

 it. It may have originated in a splitting of vii at base, and not be 

 a relic of a longitudinal separate vein. In this case the number 

 assigned to ix would be incorrect, but the numbering having been 

 introduced, to change it would make confusion, although the vein 



