10 GROTE — SPECIALIZATIOXS OF LEPIDOPTEROUS WING. [Jan. 20, 



itself would be homologous with vein viii of hind wings and not 

 with vein ix of the same pair. 



The cross-vein between cubitus and vii very gradually fades out 

 in the more specialized forms of the Papilionides and finally dis- 

 appears. It fades from its base, where it joins on to vii. upwardly, 

 becoming a mere remnant in the Teinopalpidae, extending below 

 the cubitus. Mr. Quail has discovered a similar slight blotch in 

 Anosia, and I believe correctly homologizes it with the cross- 

 vein of Papilio. I have found it still more extended in Heliconius, 

 where it reaches, running a little obliquely downward, to about 

 the place where vi would be had this latter vein not faded com- 

 pletely out. In my preparation and the original photograph of 

 Helicojiius this fragment of the cross-vein is with difficulty to be 

 seen, and I overlooked it at the time. I also failed to notice that 

 Heliconius shows a trace of vein viii. 



The presence of relics of a cross-vein below cubitus in the Lim- 

 nadidae and Heliconiidce, homologous with that in Papilio^ does not 

 necessarily imply consanguinity between the groups. The hypoth- 

 esis has suggested itself to me that the lepidopterous wing may 

 have originally shown a series of longitudinal and independent 

 veins, connected by a system of cross-veins, and without the pres- 

 ent furcations of the branches of the media and radius. The dis- 

 appearance of the cross-veins would allow of the contact of the 

 longitudinal veins, and probably assist the shifting movements we 

 now perceive in action (Proc. Am. Phil. Soc, Jan., 1898). The 

 cubital cross-vein would be a relic of these. 



General Classification. 



If we assume vein viii of the fore wing in the Hesperiades to be 

 a splitting of the vein vii at base, it might not be held to be 

 homologous with the vein viii, occupying the same position, in the 

 Sphingides and other groups of moths. This supposition seems to 

 me untenable. In the lycsenid genera Aurotis, Zephyrus and 

 Feniseca I do not perceive any difference in this vein from its 

 appearance in the Hesperiadae. It becomes simply more promi- 

 nent and somewhat less strap-like and rigid in the moths. In any 

 case, this vein viii, while allying the Hesperiades to the higher 

 groups of moths, is absent in the Papilionides and is replaced by 



