1898.] GROTE — SPECIALIZATIONS OF LEPIDOPTEROUS WING. 21 



interferes (Proc. Amer. Philos. Soc, xxxiv, 434). I also resume 

 my name for Lomanaltes Icsiulus, since from the description it must 

 be that Mr. Walker's species differs. 



General Descriptions. 



These are limited to the holarctic fauna, of which the principal 

 genera appear to have been examined. There remain, however, 

 several types I have been unable to obtain. 



Pieridce. Pierina. — Primary wings, specialization by suppression 

 of the media : Traces of the base of the media in the shape of scars 

 I have found in Eurymus and Callidryas. In Colias rhavini, 

 a mimetic form springing evidently from the same line, I fail to find 

 the least impression. Backward spurs occur in Aporia and faint 

 traces in Callidryas. The cell nowhere completely opens. The 

 cross-vein becomes partially degenerate in a number of instances. 

 In all the genera yet examined, vein iv^ , the upper branch of the 

 media, leaves the cross-vein and is given off, outside of median 

 cell, from the lower branch of radius. This character I only find 

 again on the hind wings of Nemeobius. The middle branch of 

 media leaves cross-vein above the middle and is radially inclined. 



Primary wings, suppression of radial branches : End forms of spe- 

 cialization in this direction are offered by Mancipium, Pontia and 

 Nathalis, where the five branches are reduced to three. The bulk 

 of the forms: Pieris, Eurymus, Colias, Callidryas, Eurema, etc., 

 are four-branched. As yet I find only certain of the Anthocharini, 

 therefore the more generalized group, five-branched. 



Secondary wings, suppression of media : Taking the homologies 

 as given, the vein iv^ assumes function and position of iiij on pri- 

 maries; usually the piece between its base and the issuance of iiig 

 from radius must be reckoned to cross-vein. The inauguration of 

 the movement of the movable veins appears to take place on sec- 

 ondaries generally, since in a number of Lepidoptera vein ivo re- 

 mains central on primaries, while on secondaries of same wings 

 it inclines radially or cubi tally. As on primaries, the cross- vein 

 nowhere disappears in the Pierinse and the cell remains closed. 



Other features of specialization by absorption of veins : On pri- 

 maries, vein viii is present, either as a scar or, in some instances, as 

 an apparently functional, ''tubular" vein. It takes the aspect of 

 a short, oblique, more or less rigid piece, running from vein vii to 

 internal angle. It has usually lost here the appearance of being 



