COLIIN^. 81 



the cell ; submediau vein sliglitly waved. Hindiving broadly obconical ; precostal 

 vein very short; costal vein bent upward at the precostal ; first subcostal branch at 

 one-third before end of the cell ; the cell very broad ; discocellulars very oblique, 

 lower bent near the middle, the radial from the angle ; middle median branch at 

 nearly one-fifth, and lower at nearly one-half before end of the cell ; submedian vein 

 straight, internal vein slightly curved. Body stout ; thorax clothed with long silky 

 hairs ; palpi porrect, projecting one-third beyond the head, second joint laxly 

 squamose, third short ; legs slender ; antenna gradually thickened to end, tip blunt. 

 Male. Forewing beneath with an elongated brush-like tuft of long, fine silky hairs 

 extending along the edge of the posterior niai^gin, from the base to near one-half its 

 length, this tuft is either recumbent and flattened, along the margin of the wing, 

 or, it is sometimes exserted and outspread, and is then projected in its entire 

 length, along the uppers'! de of the wing. Hindiuing above with a conspicuous 

 elongated-oval raised patch of glandular scales extending above the subcostal vein 

 to its first branch, this patch being visibly opaque on holding the wing up to the 

 light. 



Laeva. — Cylindrical, slender, granulated ; green or grey, with black dots, and 

 a lateral pale line. Feeds on Cassia [Leguminosoe). Pdpa moderately stout, pointed 

 at each end, dorsally humped. 



Type. — C. Crocale. 



Migratory Habits: in Ceylon. — Dr. N. Manders writes : " Catopsilia Pijranthe 

 occurs in Ceylon under many dift'erent forms, three of which, besides Pyranthe, have 

 received names, Ilea, Ghryseis, and Gnoma. The latter is usually called the dry- 

 season form, and Ghryseis the wet, and though Oiioma is certainly more common in 

 the dry, it is by no means confined to the dry months, neither is Ghryseis confined 

 to the luet. It may be said that all the forms occur indiscriminately all the year 

 round, and my first object was to ascertain which was the dry form and which the 

 ioet, and what would be the several effects of heat, moisture, &c., on the larvEe and 

 pupae. The first thing was to ascertain the proportion of each variety, and this I 

 left in Mr. Wickwar's hands, and in the month of February, 1903, during a 

 migratory flight, he captured sixty specimens, the weather at the time being very 



dry and hot. He mentions that 75 per cent, were males, and quite 



independently we had observed that the viet-season flight in November and December 

 were almost all females. I cannot account for this further than to say that possibly 

 during the dry months, owing to a more scanty and drier foliage, the female larvfe 

 succumbed ; whereas with the damper and more luscious foliage of the wet months 

 they had no diflieulty in surviving. The mystery of these migrations may be 

 explained, to some extent, by this preponderance of the sexes during the different 

 flights. By a coincidence, a migratory flight of butterflies was in full swing on the day 



VOL. Vll. M 



