244 PSEUDACRAEA EURYTUS 



an example of the " transition from Warning to Mimetic 

 colours " described by Poulton in the Colours of Animals, 

 pp. 221-223, that is, these butterflies possess a certain 

 degree of distastefulness compared to some others, but less 

 than others which they resemble, and so benefit by the 

 more unpleasant reputation of these latter. They are 

 Syn-aposematic and not Pseud-aposematic : MuUerian 

 and not Batesian mimics. 



I have noticed a peculiar sheen on the wings, especi- 

 ally on the under surface, that has been found very 

 useful in enabling me to distinguish the nature of a 

 specimen seen sitting far out of reach on a leaf in the sun. 



The forms with which we are concerned in this chapter 

 frequent forest, and are not to be found outside. But 

 flowering shrubs at the edge of a forest will often prove 

 extremely attractive, so that Pseudacraeas will collect 

 thereon in numbers, coming from the shady forest to 

 the bright sun at the edge, when they may be found 

 on the flower heads until shortly before sunset. On 

 Bugalla Isle, in 1912-13, I had a favourite walk along 

 the edge of the forest between 4- 30-6 p.m., visiting the 

 gamboge trees [Haronga madagascariensis), which, when 

 in full bloom, suppHed many fine Pseudacraeas, Planemas, 

 and insects of many other kinds. 



It is not proposed to mention here more than the 

 forms of eurytus which occur in Uganda, together with 

 the first known form, now known as eurytus itself, in 

 West Africa, and the Eastern and South African forms. 

 The valuable paper by Dr. Karl Jordan at the first 

 International Congress of Entomology ^ and the beauti- 

 fully illustrated book by Dr. H. Eltringham on African 

 Mimetic Butterflies, will enable the reader to gain some 

 idea of the most wonderful polymorphism of this species. 



Dr. Jordan (loc. cit.) figures thirteen West African 



males " considered to belong at least to seven distinct 



species," but says that "as a result of my inves- 



1 lere Congr^a International d'Entomologie, Bruxelles, Aout, 9110, 

 pp. 385-404. Plates zzi.-xziv. 



