158 IXIAS. By H. Fruhstorfer. 
rest on projecting twigs and leaves in the undergrowth and occur sporadically, but are sometimes, as for 
instance on Palawan, very abundant. 
aegis. Phr. aegis Fldr. (62 c), described from Mindanao, has beneath a rather broad black sub- 
illana. apical transverse band, which in specimens from the North Philippines, illana Fldr., is even more strongly 
caepia. developed. — In the much smaller caepia subsp. nov. (62 c) this band is partly effaced. The $$ vary 
strongly, no two are alike, and together with the dark principal form there are specimens with almost 
entirely white hindwing and still more extended, almost pure white median band on the forewing, $-f. 
nivata. nivata form. nov. (62 d). Underside of the hindwing dark straw-yellow. Palawan, common in January; 
gerasa'. Domoran. — gerasa subsp. nov. has a broader wing than caepia and an almost triangular black apical spot 
polisma. on the forewing without white strigae, which projects into the cell. Sula Mangoli. — polisma Hew., from 
aegina. North Celebes; in this form the black apical border of the forewing is repeated beneath. — aegina Fruhst. 
(62 c), from South Celebes, is somewhat larger than polisma, with long thin streaks in the apical area of 
the forewing, which beneath is distally only slightly tinged with white-grey. 
17. Genus: Ixias Hbn. 
The members of this genus have the same habits of flight as Huphina; in neuration they differ 
from Pieris and Appias chiefly in the shorter and broader cell of the hindwing. But judged by the shape 
of the valve they would have to be placed next to Appias. — Head rather large and like the thorax 
adorned partly with bristly, partly with silky hairs. Palpi with strongly curved basal joint and very small 
terminal one. Antenna comparatively short with pear-shaped club. Forewing with four-branched subcostal, 
of which the first two veins arise before the end of the cell, the third and fourth forming a longer fork 
than in Appias. Upper radial coincident with the subcostal to about 1 I$, in which Ixias differs essentially 
from Teracolus. 
Larva on Capparis; head small, segments 2, 8 and 4 the broadest, the rest narrowing posteriorly, 
colour uniform transparent yellowish green. Each segment from 4 to 11 bears inconspicuous reddish spots. 
Pupa canoe-shaped, strongly curved upwards and especially at the anterior end very pointed, of light ochre 
yellow colour, with a narrow, dark dorsal stripe and a fine line on each side. Pupal stage of pyrene 
14—15 days. Larvae of all sizes were found on the same bush, which was in places eaten bare by them 
(Lang). — The butterflies fly rapidly in the heat of the day from flower to flower, on which the some¬ 
what more sluggish $$ live exclusively. In districts with but little vegetation the BS are fond of 
congregating at wet places, where they introduce a pleasing variety of colour into the large crowds of 
white Pierids. Most species inhabit the hot plains, and I always found them in the greatest abundance 
not far from the sea; some species, however, prefer mountainous districts, but appear never to ascend 
above 4—5000 ft. Most of the species are common, some very local, such as venilia and balice from Java, 
and only a few races, as undatus on Borneo, really rare. Almost all the Ixias are on the wing throughout 
the year and there seems to be a continuous succession of broods; all show a tendency to form climatic 
varieties; both sexes are moreover very variable and subject to local as well as insular variation, hence 
until quite recently a considerable number of mere forms were regarded as separate species. 
I. pyrene is the most widely distributed, the most variable and at the same time the largest 
insignis. species of the genus. — insignis Btlr. (72 b) is the most northerly race known, and is distinguished from 
all the allied forms by the orange-coloured subapical spot, which extends far into the cell 
of the forewing. The $$ resemble those of pyrene (71 c), the cell is densely dusted with grey-black, but 
the white subapical band also crosses the apex of the cell, at the discocellular is placed a large isolated 
black patch, which is present also in the though much smaller, but is absent on the figure, which was 
taken from the type in the British Museum. Hindwing finely powdered over with grey and with very 
broad black distal margin, deeply dentate proximally. Not very rare at elevations of 4000 ft. in July and 
hainana. August. Formosa. — I characterise as hainana subsp. nov. a form in which the orange band only covers 
the first third of the cell of the forewing, but is still always essentially broader than in the continental 
races. The subapical band is not red-orange but a peculiar ochre-yellow, much as in salangana (72 c). 
pyrene. Hainan. — As pyrene L. we must regard the Chinese race, which Linne has named from a o of the 
dry-season form (71 c), whilst Cramer figured the $$ belonging to it as aenippe (71 $). The rainy - 
season form is much larger, all the black margins are broader and in the $ the white subapical band of 
the forewing is narrower, being sometimes nearly entirely replaced by black (71 c). The rainy-season form 
passes in collections under the names rliexia F., sesia F., evippe Drury. — In Yunnan occurs a specially 
Viensis ^ ne an( l handsome race, with the base of the hindwing above suffused with red-yellow, yunnanensis 
Fruhst., which is also distinguished by reddish instead of yellowish bands on the forewing of the $$. — 
In Tonkin we meet with a further local form with especially broad black margins to the wings and 
tonkiniana. relatively narrow, dark orange-coloured subapical spot in the <$<$, = tonkiniana Fruhst. (71 0). The $$ are 
smaller than those of yunnanensis, but have in common with them the reddish tinge of the subapical band 
