26 GROTE— SPECIALIZATIONS OF LEPIDOPTEKOUS WING. [Jan. 21, 



must rather be relegated to a distinct line, running parallel with 

 the Libytheid^e and leading to the main stem of the Hesperiades. 

 Its affinity with the Pieridae is marked by the position of iv^, which,, 

 on secondaries, has left the upper angle of cell and is fused with 

 the radius to a point much beyond the median cell, as in the Pieri- 

 nae. Since there is a parallelism in the specialization between the 

 Lycaenid group and the Pieridae in the reduction of the radial 

 branches, a further parallelism might be made to account for this, 

 especially as on primaries vein ivi is fused with radius as in the 

 Theclinae. But this will not explain the position of vein iiig on exter- 

 nal margin, the radial position of iv2 and the more unequal spacing. 

 We might appeal to the imperfection of the geological record and 

 conjure up extinct and intermediate series ; but, independent of the 

 fact that such flights of the imagination would lead us nowhere and 

 would excuse even the arrangements proposed by Mr. Meyrick, we 

 cannot do away with the main difficulty, that the wing of Nemeo- 

 bius is developed upon the Pieri-Nymphalid pattern and that we 

 should not logically graft it upon the Lycaeni-Hesperid. The 

 radius is also generalized, five-branched and cannot be derived from 

 a three to four-branched group, which it should have preceded. 

 But the five-branched Hesperiadae are formed upon another pattern 

 and could hardly have given rise to Nemeobius. The five-branched 

 Hesperiadae have most plainly produced the three to four-branched 

 Riodinidae and Lycaenidae. The wing of the latter is just what we 

 might expect from a reduction of the radial branches of Hesperia. 

 The conclusion we may come to is, that we should seek for the origin 

 of Nemeobius in an independent line, and that the structure of the 

 fore feet has been probably independently acquired. There is no 

 difficulty in this, since aborted fore feet are also characteristic of cer- 

 tain moths belonging to the Hypeninae, notably of Pallachini 

 bivittata Grt. There seems ro be a latent tendency in this direc- 

 tion whicli has broken out strongly in the day butterflies. 



General Comparisons. 



Before entering upon any comparison as to the amount of speciali- 

 zation in the Pieridae and the ^' brush-footed " butterflies (^Nym- 

 phalid^e of Scudder and Comstock) it will be well to get a mental 

 picture of the neuration of the Pieri-Nymphalid^e as a whole. This 

 can best be obtained by contrasting it with that of an allied wing 

 group in the same structural series, the Lycaeni-Hesperidae. Inde- 



