LYCANID. POLYOMMATUS, 203 
C. decidia may instantly be distinguished from C, e/na by the presence, in every variety of 
it, of a clavate longitudinal black mark at the extreme base of the forewing on the underside. 
In Sikkim it is a common species both in the lower hills and Terai, extending eastwards to Shil- 
long. Along the foot of the Himalayas it is recorded from as far west as Rohilkund, where 
Colonel Lang, R. E., took it (the z#erzptus form) in the Sal forests of the Terai in the north 
of the Pilibhit district in December. It occurs also in the Chittagong Hill Tracts ; Major C. H. E. 
Adamson has sent me a specimen taken at Bhamo, Upper Burma, in July; Mr. W, H. Irvine 
has obtained long series of it at Bholahat, in the Malda district ; as also has Mr. W. C. Taylor 
in Orissa, It is common in the Nilgiris and Ceylon, and occurs in Bombay. 
Genus 124.—POLYOMMATUS, Latreille. (PLatz X XVII). 
Polyommatus, Latreille, Sonnerat’s Buffon, vol. xiv, p. 116 (1805) ; idem, id., Gen, Crust. et Ins., vol. iv, 
Pp. 206 (1809); id., Moore, Lep. Cey., vol. i, p. 93 (1881) ; id., Distant, Rhop. Malay., p. 230 (1884). 
“ FOREWING, triangular ; cos¢a slightly arched, exteréor margin oblique and slightly convex 
towards the apex, fosterior margin straight ; costal nervere extending to half length of wing ; 
first subcostal nervule short, emitted at nearly one-half before the end of the discoidal cell, 
second subcostal short, emitted at one-fifth before the end of the discoidal cell, ¢4ird subcos- 
tal bifid, and emitted close to the end of the cell, fourth subcostal at one-half from the third 
and terminating at the apex, //#k subcostal [upper discoidal] from the end of the cell; 
[vzéddle and lower] disco-cellular nervules nearly erect, of equal length, radial [/ower discoidal] 
nervule from their middle ; d/scezdal cell broad, extending to a little beyond half length of the 
wing ; third median nervule from the end of the cell, second median at one-fifth, and first 
median at one-third before the end of the cell ; submedian nervure nearly straight. HIND- 
WING, bluntly oval, furnished with a single slender tail [at the termination of the first 
median nervule] ; costal nervuremuch arched from the base ; first subcostal nervule curved, 
emitted at one-fourth before the end of the cell ; dsco-celludar nervules very slender, upper 
disco-cellular slightly concave, discoidal nervule from their middle; third and second median 
nervules from the end of the cell, firs¢ median at one-third before the end ; submedian nervure 
straight, ¢¢/ervza/ nervure recurved, short. Bopy stouter than in Lampides, Hiibner; palpé 
porrect, long, slender, flattened, fringed beneath ; /egs slender ; aztenne with the club stout, 
grooved ; eyes hairy. Type, P. deticus, Linnzus.” (AZoore, 1. c.) 
Forewing has the first subcostal nervule emitted beyond the middle of the discoidal cell, 
quite free from the costal nervure, second subcostal emitted much nearer to the base of the 
upper discoidal than to the base of the first subcostal nervule, third subcostal emitted at about 
midway between the base of upper discoidal and apex of wing, middle and lower disco-cellular 
nervules nearly erect, of nearly equal length and slightly concave, second median ner- 
vule emitted long before the apex of the cell. Hindwing, disco-cellular nervules outwardly 
oblique, of equal length, concave ; second median nervule emitted just before the apex of the 
cell, The transformations are described under P. beticus. 
Until lately, Polyommatus has been confined toa single species, but Mr. Distant has 
described P. dagus from apparently a single female example only from Province Wellesley. 
It is not improbably an aberration or “sport ” of P. deticus, The typical species (P. beticus) 
is violet-blue on the upperside of the male, the coloration having a frosted appearance owing to 
the presence of very long hair-like scales over the entire surface. There is a conspicuous black 
marked with a black spot at the tip of each nervule. Zaz? black with a white tip. The male differs from the 
female only in having the apex of the forewing more produced.” 
‘* Closely allied to C. decidia, Hewitson, and to C. hkamatus, Moore, but differing from Ceylon specimens 
of the latter in that the black markings on the upperside of both wings are far more restricted, and on the 
underside of the hindwing the markings are much smaller and partially separated into spots.’’ (de Nicéville, 1. Cc) 
Mace and FEMALR. ‘‘ UppersIDE, _f07ew/ng white, with a blackish-brown broad costal band which -c 
widely interrupted to near the costal edge at the end of the cell, the subapical inner angle of the band acute, the 
band then extending down the exterior margin and ascending above the posterior angle into a clavate knob 
to the disc. Hindwing white, base slightly black-speckled ; a very narrow marginal band traversed by white 
lunules along the outer edge. UnpersipE marked similarly to C. decédia, Hewitson.”’ (Moore, \. c.) 
“Bombay ” (Moore). ‘* Found commonly on the lower slopes of the Nilgiris. ’ (G. F. Havepson). 
as above recorded this form has been taken in the Sal forests of the Terai in the North of Rohilkund in 
December by Colonel Lang. 
