30 GROTE — SPECIALIZ ATIOXS OF LEPIDOPTEROUS WING. [AprU 7, 



The comparative characters are those of generalization, so that 

 Ornithoptera presents features which the rest of the Papilionides 

 have probably abandoned. In the same way I assume that the 

 species of Euryjjius (^CoUas Auct.) have passed through a Megan- 

 ostoma stage, and the entire extant Pieridae an Anihocharis stage, 

 in which latter the Radius was five-branched and generalized. 

 There is a strangeness about Ortiithoptera, suggesting a separate 

 origin. This disappears with the higher forms of the Papilionides, 

 which have come to look much like other butterflies. Tlie remain- 

 ing generic types may be now gone over in review. As far as pos- 

 sible I take the generic titles in their chronological order. 



(2d Group.) 

 Zetides sarpedon. 



Agrees with Idaides, except that the secondaries are bluntly pro- 

 duced inferiorly and are without a tail. Vein ivj lies somewhat 

 nearer ivg at base. In both genera the excision at anal angle is 

 long, owing to the produced wing, but vein vii is not relatively 

 shorter, as in Euryciis (3d Group). Zetides appears more special- 

 ized than Idaides. The differences are small, but may be consid- 

 ered as of generic importance. 



Arisbe similis. 



Agrees with Idaides, except that the secondaries are not produced 

 inferiorly ; the outer margin is rounded, without salient projection. 

 The anal excision is shorter. The position of iv^ on secondaries is 

 more central, and this appears a more generalized form than either 

 Idaides or Zetides. 



I am indebted to the kindness of Dr. Karl Jordan for material of 

 this species. Notwithstanding the differences in shape of hind 

 wings, these three genera are undoubtedly phylogenetically nearly 

 related. The veins are opaque and strong. 



Pathysa antiphates. 



Agrees in one essential neurational feature, the fusion of the first 

 radial branch, with the preceding genera, to which, notwithstanding 

 ''superficial " discrepancies, it may thus be distantly related. The 

 cubital cross-vein is attenuate, and does not reach vein vii. On 

 the secondaries the position of iVj is nearly central. Vein ivg is 

 produced into a long tail, not spatulate. In shape of wing this 

 genus resembles Iphiciides, as also in the slender, transparent 



