99 BRITISH BUTTERFLIES 
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however, more decisive, although the distinction, though not easily described in words, is readily seized by an 
experienced eye. The Blues are altogether without tails, and their character is well preserved in the oriental 
tropical regions ; but it is remarkable that in that part of the world no true Coppers have been discovered, which, 
in Europe, chiefly constitute the present genus. 
The relationship of this genus with that of the Blues is indeed very close, and we accordingly find considerable 
diversity of opinion as to the employment of the generic names of the two groups. Latreille in all his 
works employed the name Polyommatus for the whole of the species of the present family, giving at the 
first our Thecla as the primary division, whilst in his late works he gives one of the Blues as an example of the 
genus. Fabricius separated some of the Iair-streaks under the name of Thecla, retaining the Blues and Coppers, 
together with a great number of foreign species, under the name of Lycena, which name Ochsenheimer 
employed, arranging, however, the entire family under this generic name, and forming the Blues, Coppers, and 
Hair-streaks into three groups or families. Mr. Curtis, in his British Entomology, gave the Blues and Coppers 
under the genus Lyczena ; but in his Guide he has adopted the nomenclature of Mr. Stephens, namely Thecla for 
the Hair-streaks, Lyczna for the Coppers, and Polyommatus for the Blues. 
Dr. Horsfield, in his beautiful work on the Lepidoptera of Java (which, it is to be hoped, will still be completed, 
at least as far as regards the diurnal Lepidoptera), placed in the genus Polyommatus only two Javanese species 
allied to P. Alsus and P. Argiolus, but greatly enlarged the limits of Lycana, making it comprise many Blues ; whilst 
Boisduval adopts the name Lyczna for exotic insects, such as P. Beeticus, Linn., calling our Blues by the name 
of Argus, taken up from Scopoli and Geoffroy, and our Coppers Polyommatus. 
Such is one of the many instances of confusion to be met with in the works of modern entomologists, owing to 
the want of some fixed principle regulating the adoption of old generic names when the genera are required to be 
cut up into minor groups. The names both of Lycxna and Polyommatus were, as we have seen, intended 
to indicate groups of greater extent than our present genera. If, therefore, we form our Coppers into one 
group, and our Blues into another, the generic names Lycena and Polyommatus, as intended by their original 
proposers, are not applicable thereto, unless indeed we can ascertain that they were regarded by the proposers of 
such names as their types: and we have seen that such is not the case with either name; the Hair-streaks being 
placed at first at the head of Polyommatus by Latreille, whilst we find the Coppers at the end of the genus 
Lycena of Fabricius. The Purple Emperor, again, is placed at the head of the Argus group by Geoffroy, which 
also includes the Blues and the Coppers. In such cases my opinion is that (in order to avoid such distracting 
confusion) wherever a species or division of a genus is separated from an old genus, 2 new name ought to be given 
to it, unless such species or division be the true type of the old genus, when, of course, it will retain the old generic 
name. Instances might be pointed out in which entomologists are agreed as to the nomenclature of a group, 
although, from the non-adoption of some such principle as this, an old generic name has been abstracted from the 
true type of a genus and conferred upon an aberrant species ; but in the case of the Copper and Blue Butterflies no 
such uniformity of opinion prevails, each writer having acted without any principle. In the present instance, 
therefore, I feel no hesitation in rejecting the nomenclature of recent Lepidopterologists, being convinced that a 
revision of the entire family Lyceenide will necessitate the establishment of a much greater number of named 
groups, when the name of Lyczna will have to be restored to the true type of the genus. I have, therefore, 
adopted Hubner’s name Chrysophanus for the present group, which is quite expressive of their splendid 
appearance, being derived from the Greek words xpvods, gold, and aivw, to appear. 
