160 
DERCAS. By H. Fruhstorfer. 
nola. 
venilia. 
piepersi. 
vollenhovii. 
reinwardti. 
kangeana. 
baliensis. 
lombokiana. 
noctulci. 
reinwardti. 
pagen- 
stecheri. 
kuehni. 
verhuelli. 
rufolineata. 
skertchlyi. 
doubledayi. 
form. — Finally, an especially extreme form of the rainless period, from Mahableswar in northern Bombay, 
has been described as nola Swinh. (72 b). 
I. venilia Godt. (72 d) occurs exclusively on Java and is even there very local, being met within 
numbers only in the south of the province of Kediri. The $$ vary somewhat; besides the form figured, 
with yellow upper surface and red-orange-coloured subapical spot, there are also some which have the upper 
surface pure white, with a deep yellow transverse band, in which at the discocellular there are only traces 
of a cadmium-yellow tinge. These are a U° beneath predominantly white, with yellowish margins. 
I. piepersi Snell, is the only species of the genus which I have not before me; it is intermediate 
between venilia and reinwardti, but is larger than the former, piepersi occurs at Loka at the Peak of 
Bonthain and at the Waterfall of Bonthain and is even there very rare. There are 2 <$<$ in the Berlin 
Museum; the species is still wanting in the British Museum. 
I. vollenhovii Wall. (72 d) inhabits the islands of the Timor Group and Timor itself. The $ figured 
belongs to the rainy-season form; the dry-season form is only a little inferior in size. In it the black 
distal margin of the hindwing is suppressed and the under surface assumes a pale white-yellow tone. 
1. reinwardti VollenJi. (72 e) occurs on all the islands from Ivangean and Bali to Timor and Alor, 
and is everywhere common. It forms an ornament of the coast districts in which, on Lombok, it flies in 
large numbers. The $3 arc swift fliers and visit flowers, but on specially hot days congregate at moist 
river-banks in small groups. The flutter through thorn-bushes and are fond of hiding among thorny, 
arborescent Euphorbiaceae. — kangeana subsp. nov. (72 d) differs from the more easterly races in the much 
smaller yellowish red discal spot, the very thick black veins of the forewing and the specially deeply 
dentate distal border of the hindwing. Under surface of both wings very sparsely marbled with brown. 
Ivangean. — baliensis Fruhst. (= pulchrior Btlr.) is the form from Bali, hitherto only known in 2 ($<$, but 
which may probably also occur in eastern Java. The $ is characterised by a very large blue-dusted basal 
area, a very light discal spot posteriorly bordered with intensive yellow, and by fine black transverse 
stripes on the forewing. — lombokiana subsp. nov. (72 e) differs from the name-type (which was probably 
described from Timor or Flores) in the smaller dark red median spot and the large roundish submarginal 
patches of the forewing. The $ occurs in three forms: the one figured (72 e) with yellow upper surface; 
an intermediate form noctula form. nov. (72 e), almost entirely black, occurring in the wet season; and a 
variety with white upper surface, belonging to the dry period. — reinwardti Vollenh., of which we figure 
the dry-season form (72 e), has the underside of the hindwing in the UcJ P a 'l e yellowish white. The brood 
of the rainy season is a little larger, more broadly striped with black; the (JU beneath yellow, with strong 
brown submarginal spots. The $ recalls noctula, but is larger, the forewing beneath with greenish yellow 
cell, broad yellow-grey stripes beyond the cell, base of the hindwing dark ochre-yellow with very broad 
violet-black distal margin variegated with yellow. Flores, Timor, Sumbawa, Alor. — pagenstecheri Bob. 
differs in the of which only the white dry-season form is known to me, in the broader black dis¬ 
cocellular band of the forewing; Sumba. 
I. kuehni Bob. (72 d(£, 78 a $) is a completely modified reinwardti, whose $ exhibits a retrogression 
to the pyrene-group in the bright orange-eoloured transverse band on the forewing above. The cell of 
the forewing is entirely black. There are two $-forms, the one figured with entirely white upper surface 
to both wings and one with the wings light yellow above, which latter was already known to the author 
of the species. Wetter. 
18. Genus: Dercas Dbl. 
The principal characteristic of this genus consists in the short but very broad cell of the foreAving, 
which scarcely reaches to y 3 of the Avdng. The second subcostal vein arises exactly at the apex of the 
cell and the third and fourth veins form a large fork. Precostal vein of the hindwing relatively long, 
straight. Antenna short, gradually thickened. ForeAving either deeply dentate or Avith the apex much 
produced. — Only a few species, of rapid flight; they are nowhere A T ery rare, without, hoAveA r er, occurring 
in great abundance. In contrast to their nearest allies, Gonepteryx and Catopsilia, they are divided at 
very short distances into geographical races. All the species occur in the mountains but at medium 
heights and have scarcely been observed above 4000 ft. 
D. verhuelli, described from China, where it occurs in Hong-kong and in the Canton district, not 
being very rare. I met with the species also in Tonkin, where it occurs in three forms: namely as forma 
verhuelli Hoev., which was figured in the Palearctic part (vol. I, 27 e). §-form rufolineata form. nov. 
(67 c), in which the red longitudinal stripes are even more strongly expressed than in the principal form, 
but the black distal margin is much narrower; and a £-form which Niceville has described as sker¬ 
tchlyi (67 c), with likewise reduced distal margin but Avithout a trace of reddish longitudinal bands. -—- 
In India proper tAvo local races may be separated: doubledayi Moore (= menandrus Fruhst. i. 1.) (67 d, 
