LYCENIDA. ARHOPALA. 235 
“ Thisis an abundant lycenid in the Malay Peninsula, and its distribution extends 
through Tenasserim into Burma, but, owing to the confusion as to identity, its snows 
geographical area is somewhat difficult to ascertain.” (Déstant, 1. c.) 
The solitary character by which I can distinguish the true 4. centaurus, Fabricius, 
from the north-east Indian local race, A. firithous, Moore, is that the male on the upperside 
has an extremely narrow outer black margin, which is almost confined to the cilia, while in 
A. pirithous this black border is a good deal wider, though still narrow. True A. centeurus 
eccurs throughout Burma, and thence southwards to Singapore, in Nias Island, Sumatra, and 
Borneo. I append a description of this form, which was described by Felder as a distinct 
species under the name 4. zakula.* 
Local race firithous, Moore. Descriprion: ‘‘ Allied to MW. [=4.] nakula, Felder, 
{=true A. centaurus, Fabricius). MALE. UPPERSIDE, doth wings differ in being of a pale 
purplish-blue, also witha black narrow marginal band. UNDERSIDE, do/4 wings darker. 
forewing with the markings less distinct, the inter-discal space bordering the lunular bands 
dusky purplish iron-grey. Mindwing with similarly disposed markings, which are all dusky 
purplish iron-grey, more strongly defined in the male than in the female. FEMALE. UPPERSIDE, 
both wings of a brighter purple-blue thanin JV. zakula.” UNDERSIDE, both wings as in the male. 
‘© N. centaurus, Fabricius, and JV. pseudocentaurus, Doubleday, are both distinct from the 
above.” (doore, 1. c.) 
Placing side by side fresh male specimens of true A. cexfaurus from Singapore and fresh 
specimens of A. firithous from Sikkim and Assam, I can detect no difference in the shade of 
purple, the solitary character which separates the local race pivithous from true cenfaurus being, 
as stated above, the rather broader outer black margin to both wings on the upperside of the 
male. The undersides are equally variable in both forms, and there are no distinguishing 
features whatever between their respective females. This local race occurs commonly at low 
elevations in Sikkim and throughout Assam, 
Local race Zérama, Moore. DESCRIPTION: “MALE. UPPERSIDE, both wings brilliant 
ultramarine-blue, with a marginal black band. UNDERSIDE, doth wings brown, suffused 
with purple-grey. Forewing with slender white-bordered discoidal marks, less defined discal 
band, streaks below the cell, and submarginal fascie. AHdwing with very indistinct browner 
basal spots, discal band, and submarginal lunular line ; a few green speckles above the 
* Amblypodia nakula, Felder, Wein. Ent. Monatsch., vol. iv, p. 395, n. 4 (1860); Arhopala wxakula, id., 
Reise Novara, Lep., vol. ii, p. 222,n. 244, pl. xxix, fig. 14 (1865). Hapirat: Malacca interior, Sumatra 
EXPpANSE ; 2°3 inches. Description: ‘* Wings shortly tailed. UppersIpDE, doth wings deep violet-cyaneous. 
UNDERSIDE, doth wings deep brown. Forewing with three fuscous cellular spots circled with bluish, anda 
pair of exterior fuscous fascie circled with whitish. A7mdwzng with differently-shaped basal spots, an irregular 
discal fascia and a posterior undate striga fuscous circled with paler, three anal black lunules most densely 
sprinkled with cyaneous-greenish. FEMALE, UPPERSIDE, doth wings deep violet-cyaneous. Forewing with 
the costa, the apical and external borders, hindwzng with the costa broadly and the anal margin fuscous.” 
‘* Allied to A. centaurus, Fabricius.” 
“* English authors from the celebrated Horsfield to Moore (whom he had the good fortune to have as his 
successor) combine under this one name [A 7zdlyfodza] very difierent species ; but we consider Boisduval’s name 
Arhopala more suitable for these insects, so remarkable for their antenne being so slightly clavate ; as how- 
ever this name has not yet been published witha description, we retain for the present Horsfield’s name.” 
(Felder, |. c., in Wien. Ent. Monatsch.) 
“Mace. UpPERSIDE, doth wings violet-blue, very narrowly blackish-fuscous on the costa and the exterior 
margin. A7zzdwing with the costal and interior margins fuscous. UNDERSIDE, é0¢h wings reddish -fuscous. 
Forewing pale over nearly the interior half, a pair of rings in the cell and a spot closing the cell, of a deeper 
tint and partly encircled with metallic whitish-green ; and the following fuscous markings obsoletely margined 
with whitish :—two interior spots interiorly diffuse, and a very narrow exterior fascia which is chain-like and 
broken posteriorly. Aindwing with the following olive-fuscous markings bordered with a deeper fuscous, 
and then obsoletely with glaucous and whitish :—five basal spots, an irregular small fascia posteriorly interrupted 
and joined to a wavy discal fascia, alsoa deeper fuscous wavy and dentated exterior striga bordered on all 
sides with paler atoms, and another submarginal striga formed of lunules, and three anal lunules distinct from 
these black, and powdered with metallic green. FEMALE, UpperRSIDE, doth wings of a paler tint thanin the 
male, with the costal and exterior border, fuscous (the latter very narrow in the hindwing). UNpeErsipeE, doth 
wings, as in the male.” 
** A local from of the A. centaurus, Fabricius, of Continental India, it differs very constantly from this, 
as also from the Javan A. pseudocentaurus, Doubleday, in the colouring of the macular bands of the under- 
side of the hindwing. It recedes also from the former in the blunter apex and in the moderately straight 
exterior margin of the forewing.”” (/e/der, 1. c. in Reise Novara). 
_ The prominence and shade of colour of all the markings on the underside in all forms of A, centaurus 
being extremely variable, no species or local race can be based on those characters alone, 
