36 GROTE — SPECIALIZATION'S OF LEPIDOPTEROUS WING. [Jan. 21, 



charis for the type belemia, which is, perhaps, identical. The 

 subjective question of whether there are two '' genera " to be con- 

 sidered is not of any importance to me at all. I recognize two 

 five-branched types : the one specialized, which I seem warranted 

 in calling Anthocharis under Boisduval's original use of that term; 

 the other, relatively generalized, which I call Euchloe, with the 

 type given by Mr. Scudder of cardamines. 



The white Anthocharids differ from the type of Euchhe carda- 

 mines in that vein iii2 has moved from the original position and is 

 given off opposite, or even beyond the cross-vein. \wA. ausomdes, 

 which is slightly the more specialized of the three examined, it has 

 even passed the extremity of the cell for a considerable distance. 

 Therefore the specialization runs here upon the same line as in the 

 case of Meganostoma and Eurymus. The generic title Anthocharis 

 should have, I believe, the type belemia, in case genutia does not 

 share these essential characters and is not, in the sense here pro- 

 posed, an Anthocharis. It is clear from the above citation from 

 the Historical Sketch, that Mr. Scudder has misapprehended the 

 state of affairs in this group ; for I am quite unable to find any 

 neurational differences between the North American E. stella and 

 the European type of Euchloe. In both insects vein iiia retains its 

 original position above the cell. And the chances seem to be that 

 this will be the case with most of the species, carrying an orange 

 blotch on the male primary, irrespective of locality. In any case, 

 that which interests us here especially is the development of a 

 specializing movement tending generally in the direction of a 

 reduction in the number of the radial branches, but here taking a 

 special and, looking through the day butterflies, perhaps an unusual 

 direction. I find it, besides in these two instances, in the Pieridae, 

 in Euptoieta, Melitaea, Euphydryas, Araschnia and Heliconius. 

 But when we examine Pontia, we find that, although the five- 

 branched radius has become a three-branched, still vein iii.^ has not 

 changed its place. The reduction has been effected by other 

 means than the shifting of iiij in the direction of the apex of the 

 wing. Into the details of the physiological process of absorption 

 I cannot now enter, sufficient for my present purpose is the fact, 

 that Pontia represents a clean descent from Euchloe-like forms and 

 that it has not passed through Anthocharid-like forms upon its 

 way. The absorption of iii^ has proceeded to a varying extent in 

 these species of Anthocharis. The little branch remaining has 



