LYCANID. ARHOPALA. 227 
The genus Arhofala was instituted by Boisduval for the reception of two new species of 
butterflies, the one from Papua which he named 4. phryxus, and the other from the Aru Islands 
which he named 4. meander, He gave no diagnosis of the genus, except that the insects are 
rather large, and the only authors who have used it in the sense understood in_ this work, and, 
indeed, at all, are Drs. Staudinger and Felder, The former eminent writer quite correctly saw 
that the genus Amddypodia of Horsfield, of which narada, Horsfield, is the type, differs so entirely 
in structure and facies from the mass of butterflies generally placed under that name that it could 
not be correctly used for them. During the last ten years Mr. Moore has tried to split up the 
genus Arhopala by proposing seven new genera. Mr. Distant in his “ Khopalocera Malayana” 
refers to four of these only, and sinks two of them as synonyms, retaining two only as distinct, but 
with much doubt. He ignores the two genera Darasana and Mahathala of Mr. Moore, and the 
Arhopala of Dr. Felder, entirely, though representatives of all of them occur in the Malay penin« 
sula. Having very carefully examined the neuration and outline of the wings of these seven genera 
of Mr. Moore, I have no hesitation in sinking five of them as synonyms, and I retain two of them 
with great reluctance, v¢'z., AZakathala for a single species which presents two very aberrant fea~ 
tures, and Acesina with two species, which have rather a peculiar /acies as regards the markings 
of the underside. In the above diagnosis of the genus Arhofala, Ihave tried to point out 
the chief differences that exist in the structure of the insects of this genus. It will be noticed that 
the venation differs but little, but the outline of the wings, especially of the hindwing, is very 
variable. I find it impossible, however, to draw any line of demarcation between the species 
which would enable them to be distinguished as belonging to distinct genera, much as I should 
like to be able to doso. The genus as it stands is most unwieldy, but it is no gain either to 
science or to convenience to imagine generic distinctions where none exist. The most obvious 
structural character is the presence or absence of a tail or tails to the hindwing, but in the 
same page in which Mr. Moore described the genus Panchala he placed under it tailed and tailless 
species. And so with the other genera, though he gives the presence or absence of the tail as 
a generic character, he indiscriminately mixes up species with and without tails under the 
same generic name. Generic characters may still be found by which to divide these butterflies 
satisfactorily when the eggs, the prehensores of the males, and the legs of both sexes come to be 
examined, but it appears to me hopeless to look further for such characters in either venation or 
outline of wings. Mr. Doherty’s proposed new genera, //os and Jo’s, cannot properly be dis 
cussed here, as no diagnosis of them has been written. 
An Arhopala is unmistakable, the merest tyro in Oriental butterflies should at once be 
able to distinguish any species as belonging to the genus, which contains some of the 
largest as well as most beautiful of oriental Zycenide. Nearly all the species are of 
some shade of blue or purple on a black ground on the upperside, the females with the blue 
or purple colour always more restricted than in the male. A few species of the eumolphus 
group are, however, brilliant shining green on the upperside of the males, but their females are of 
the ordinary purple type.* Most fortunately the undersides of both sexes are practically marked. 
* Since the above was written, Mr. Doherty has lent me the MS. of a paper to be hereafter published, 
in which the following most interesting note is given :—‘‘ A word deserves to be spoken on the subject of 
reen butterflies, since it seems one little understood at home. Early in the century Horsfield professed to 
=e found a green female of the alge Arhopala eumolphus, Cramer, the true female of which is blue, 
Recently Mr. Distant has described as the female of his A. farguhariz, a butterfly bright green over the 
basal half of the wings above. Now the real female of A. /arguharii (perhaps the form described as “ Nara. 
thura” maxwellii, Distant) is violet-blue, and one of the most constant of butterflies. Ofthe green form 
mentioned I have taken several specimens in the Malay Peninsula and in Borneo, and they are all males. It is 
a rare species, undescribed, perhaps identical with the Horsfieldian form.” 
‘Grant Allen shews that while greenish flowers are amongst the oldest, really green flowers are the most 
recently developed of all, and among the most conspicuous. Very much the same thing is true of Lepidoptera. 
Pale green moths like Actias, Geometra and Pyralis are protected by their colouring which is common 
to both sexes, and are quite hidden when resting among the leaves. Such seems also to be the case with 
Lehera eryx, Linneus, a lycanid which is greenish on the desde, and may possibly be the case with 
some Catofsilias(a genus of the next subfamily, the Pzerine or ‘ Whites]. But bright metallic-green 
is, I think, the latest-developed colour among butterflies, and decidedly the most conspicuous. No one who 
has not seen it can imagine the brilliancy of Arhopala farquharii or Ornithoptera brookeana, Wallace, 
[Ornithoplera is a genus or subgenus of the Pafilionine] in the greenest jungle. The brightest of the metallic: 
blue butterflies look dim beside them. It may be confidently asserted of all such butterflies, that unless the 
species is protected, only the male is green. The protected Ornithopleras have sometimes assumed green 
.colours as well as golden and orange, and the female shares in this useful ornamentation to aslight degrees 
