THE ATHALIA GROUP OF THE GENUS MELlT^A. 99 



An aberrational form of this species was described and 

 figured in the ' Bulletin de la Society L6pidopterologique de 

 Geneve,' vol. i. pt. iii. p. 262, pi. 8, fig. 5 (1908), under the 

 name of ab. alba, Eehfous. It is described as follows: "la 

 couleur du fond, normalement fauve, est remplacee par du blanc 

 pur. Sur le dessus des ailes il ne reste pas la moindre parcelle 

 de la couleur normale ; les dessins fonc6s n'entourent que du 

 blanc. Dessous, de legeres traces de fauve se retrouvent sur 

 les nervures et de chaque cbt6 des lignes noires."* This appears 

 to be a singularly perfect form of albino, for the colouring matter 

 is absent not only from the ordinary fulvous scales but from 

 the feathery portion at the base of the wings, from the fringes, 

 and to a great extent from the palpi and legs. This example 

 was taken at Iselle on the south side of the Simplon on July 14th, 

 1907, and in the same paper another similar specimen is men- 

 tioned as having been taken near Geneva on July 13th, 1904. 

 With regard to the species to which these aberrations are 

 referred, the dates would seem to leave no doubt as to the 

 correctness of the diagnosis, even if the illustration of M. 

 Eehfous's specimen were not in itself conclusive. In a footnote 

 it is added that the name is intended to serve as a concise 

 description, and to apply not only to the species to which these 

 particular examples belong but to similar aberrations of other 

 species ; M. dictijnna, M. didyma, Argynnis (Brenthis) selene, 

 and A. {Issoria) lathonia are specially mentioned. It will indeed 

 be an advantage if this extended definition be accepted and 

 adhered to more completely than has been done in the similar 

 but far more extended case of the Lycsenid aberrational forms 

 dealt with by Courvoisier in the ' Bulletin de la Societe Entomo- 

 logique Suisse,' vol. xi., pt. i., pp. 18-25, pi. ii. (1903^ where 

 general names applicable to all the usual forms of aberration 

 common to several species were suggested. Some of these were 

 no doubt barred in certain cases by the "law of priority," but 

 in all others these names ought certainly to have been accepted, 

 even if this be not a case (as I most strongly hold it to be) where 

 this apparently iron law of priority should have been made to 

 bend. Surely it is not now outside the range of practical 

 politics to press for the formation of an international council 

 by which all such questions should be definitely decided ? There 

 are, of course, certain obvious difficulties in the way, and in 

 making the attempt, others, unforeseen, would probably come 

 to light, but none appear to be of such a character as to be 

 necessarily insurmountable, and the result in clearness of 

 meaning, in saving of time and labour, and in turning valuable 



■'■ The ground colour, normally fulvous, is replaced by pure white ; on 

 the upper side of the wings there does not remain the slightest particle of 

 the normal colour, the dark design surrounds nothing but white. Beneath, 

 slight traces of the fulvous again appear on the nervures, and at each side 

 of the black lines. 



