157 



Among the large number of P. oregonius very few have this 

 border straight, and only one a little convex. Among P. Zoli- 

 caon one from Mendocino and one from Washington Territory 

 have the margin as convex as P. aliaska. Among the Asiatic 

 specimens those from Kamschatka and two from Koolloo, Hima- 

 laya, have the margin convex, several others only a straight mar- 

 gin. Among the European specimens before me some have 

 a straight margin, none a convex one. But the two varieties 

 quoted before as figured by Ver Huell and Freyer have a convex 

 margin. I think if even all Hudson's Bay and Aliaska specimens 

 should possess a convex margin, this can only be considered to 

 be a local variation. Messrs. Scudder and Edwards do not men- 

 tion the shortness of the tail ; after all, my measures show its 

 extreme variability. 



The second difference noted by Mr. Edwards, that the black 

 parts are more intensely colored and less dusted by yellow scales, 

 and the nervules very considerably edged with black, is not true 

 for P. aliaska. The large material before me proves this state- 

 ment for the Himalayan specimens, and even for some European 

 ones to be incorrect. 



I have given considerable attention to another difference ; 

 the black sub-marginal band of the primaries between the yellow 

 part and the row of yellow spots near the margin. Mr. Scudder 

 has used the same character for the band on the upper side of 

 the wing. I speak here only about the same band on the under- 

 side of the wing. It is very rarely entirely black, mostly more or 

 less dusted with yellow scales in the middle of each cell. I find 

 it entirely black in one P. Zolicaon from California, and three P. 

 oregonia from Washington Territory. Mostly the yellow dust in 

 the cells is connected to form a narrow or larger yellow middle 

 line. Finally the band becomes yellowish-gray, bordered on both 

 sides by a black line, the internal one broader. Near the anal 

 margin the end of the band remains mostly black ; near the costal 

 margin the large marginal cell connected with the band is entirely 

 black, or in part, or entirely yellow, with a broad black border on 

 its basal end. The sub-marginal band is equally broad through- 

 out or narrowed in approaching the costal margin. In the latter 

 case two different ways are followed ; or the inner margin of the 

 band is straight to the tip and only gently sloping to the external 

 margin, forming a more or less pointed band, or the two last cells 

 have the internal black border removed more outwardly, so that 

 those cells are similar to the steps of a stair. There exist inter- 

 mediate forms where the internal margin of the second cell is 

 oblique and connected at its base with the margin of the third 

 cell so that this part of the band is sloping. 



P. machaon from Europe has this band mostly straight, only 

 the first cell narrower, broad 4 mm., first cell 2 mm., or broad 3 

 mm., first cell 2 mm. Some specimens from Austria, Alsace. 



