23 



E. J. In the Tengger, Semarou and Arjouno mountains the form Bromo 

 Fruhst. occurs in which the mixture of white and yellow on the upper-side of 

 the hind-wings is still much more yellowish, but which is principally characterized 

 by the amount of red on the upper-side near the basis of the hind-wings, 

 whereas this red in the W. J. form is almost entirely replaced by black. 

 This is a phenomenon of colour-evolution, as is clearly proved from the circum- 

 stance that also in the specimens from W. J., when magnified, several red 

 scales become visible in that place, and which are thus probably relics of the 

 red which was there formerly, as it is now still in the form Bromo. The form 

 Crithoe has in this respect advanced further than Bromo in the colour- 

 evolution, a circumstance to which also refers the fact, already mentioned, that 

 the yellow whitish on the upper-side of the hind-wings in the form Crithoe 

 may still be called yellow in Bromo. This may be a result of some local 

 influence, but also more likely only of the circumstance that the separation, 

 caused by the lower country between, has turned these butterflies of the eastern 

 and of the western mountains into two separate races, in each of w^hich the 

 evolutional development continued its course independently. 



A similar difference of race between butterflies of the same mountains 

 shows itself also in Papilio Arjuno Horsf. 



The early stages of this species are still unknown, I once found a chrysalis 

 on a shrub, on which there were also many Loranthus leaves, which had been 

 already gnawed, and from this pupa there emerged a specimen of this species. 

 But according to the description I then made, this pupa differs so strongly 

 from other Thyca pupae that, fearing a mistake, I do not wish to publish that 

 description yet. 



3. Belsiama Cram. (PI. II, fig. 4, a, b, c, d, e, /, g). 



Cramer, ////. 114 //. 258 A — D (1782) Pap. Belisama. 



HoRSFiELD, Cat. Lcp. E. I. C. I //. 4 7%. loa — c (1857). Pieris „ 



BoiSDUVAL, Spec. Gdn. I p. 464 (1836) „ „ 



Snell. v. Voll., Mon. d. Pier. p. 16 (1863) . , . . . „ „ 



Smith-Kirby, Rhop. Exot. pi. 19 {Delias I) fig. i — 4 (i88g). Delias Nakula. 



Staud., Iris IV p. 78 (189 1) „ Belisama. 



In the year 1863 and from 1864 — 1869 when I resided at Batavia (3 — 14) 

 and studied the butterflies, I never found this species there. Yet it catches 

 the eye by its size and its very striking coloration, the more so as it flies, 

 not very fast and at moderate heights, on the trees, and, moreover, I had 



