THE ATHALIA GROUP OF THE GENUS MELITffiA. 199 



are invariably laid, and L. minor, on which the caterpillar feeds 

 in preference after it is half grown ; and because it has the fol- 

 lowing constant characters : (1) an elongated form of wing ; 



(2) the two basal black lines on the fore wing straight and parallel ; 



(3) the border of the hind wing upper side so broad as almost to 

 cover the lunules ; (4) the median light band of the hind wing 

 under side very narrow and the general arrangement of that 

 wing like that of deione. He then continues thus : " To these 

 characteristics may be added the following, which are equally 

 constant : on the under side of the fore wing, in the space 

 corresponding with the lower portion of the median band, this 

 species has always and invariably a black mark like a Y placed 

 horizontally and opening outwards >- thus, a mark which is not 

 met with in any other species, not even in deione, which, as we 

 have said, resembles it the most closely ; this mark is also visible 

 on the upper side of the same wings. On the under side of the 

 hind wing, between the basal and median rows of spots, is a tri- 

 angular spot, whose lower acute angle rests on the last spot of 

 the basal band, which gives a slight resemblance to M. deione 

 but to no other species. Its flight also is more sustained and 

 less jerky." While fully concurring in the two latter distinc- 

 tions, especially in his observation on the triangular spot which 

 is conspicuously characteristic, I must observe that his remarks 

 on the Y-mark go somewhat beyond what is warranted by more 

 recently ascertained facts. In the first place, it is by no means 

 so invariable in berisalensis as is here stated, the mark often 

 becomes an italic x placed sideways, especially on the upper 

 side, and occasionally like parentheses placed horizontally and 

 back to back thus x ; sometimes it even becomes an oblong black 

 patch, with mere indications of the fork of the Y at the outer 

 corners. Secondly, the mark does frequently occur in deione, 

 and the elements of it are, so far as I have seen, almost always 

 present in that species, which we now regard as the type-form 

 of berisalensis. Thirdly, it is not confined even to the different 

 forms of this species ; Mr. Prideaux has a male athalia from 

 Wiesbaden in which it is very distinct, and it is also frequent in 

 hritomartis, either as a light mark enclosed in a black patch, or 

 more rarely as the shape of the black mark itself. Although I 

 am treating this insect separately, I still adhere to my previously 

 expressed opinion that it is a local race of deione ,- of this I was 

 at one time uncertain, but a comparison with Spanish forms 

 seems to add great weight to this probability. They mostly 

 agree more closely with this form than with the typical French 

 races. Those specimens which I previously (' Butterflies of 

 Switzerland ') described as being lighter than the French prove 

 not to have been Spanish at all, though Pyrenean, my informant 

 apparently having taken it for granted that the latter implied 

 the former ! One further point occurs in Chanoine Favre's 



