Notes on Seasonal Dimorphism. 559 



We now como to the second group in whicli the 

 seasonal forms are very distinct, and not generally recog- 

 nised as such. I will deal with them in the order given 

 in my list above. 



(1.) P. ceryne, Boisd. ^P. tuhuoa, Wallg. I have never 

 met with these species commonly in life, and am, there- 

 fore, unable, to speak from personal experience, but Mr. 

 Hutchinson, of Estcourt, and Mr. Barker, of Malvern, 

 who have both collected for many years in such different 

 parts of Natal, assure me that they are convinced that 

 tuhuoa is only the dry season form of ceryne. Trimen, 

 too, notes the close relationship of the species ; indeed, 

 in former years he held them to be the same. They ex- 

 hibit just the differences one would expect in this genus, 

 the bright tints of ceryne being replaced in tuhuoa by 

 duller colours, the latter also having the ocelli reduced 

 and the forewings strongly falcated. 



(2.) P. simia, Wallg. = P. cuama, Hew. These two 

 so-called species are not common just round Salis- 

 bury; but in the upper Mazoe River and middle Umfuli 

 River they are abundant ; and I have had excellent oppor- 

 tunities of observing the gradual change from dry to wet 

 season forms, though, unfortunately not vice versa. This 

 is a very interesting case of variation owing to the dis- 

 tinct gradations exhibited between the two forms, which 

 may be grouped as follows, according to season : — 



(a) Midsummer Form. — The typical, small, heavily- 

 marked P. simia, Wallg. 



{h) Early Summer Form. — The larger, more lightly 

 marked form of simia, with tendency to white 

 clouding on upperside, described by Trimen as 

 a variety (P. Z. S., IG Jan., 1894). 



(c) Late Winter Form. — P. cuama, Hew., in which 

 the underside is very much darker and more 

 overclouded than in simia, though the markings 

 are precisely similar and well defined, showing 

 a preliminary sign of the midrib line. Apices 

 of forewings falcate. 



(rf) Midwinter Form. — Cuama, in which the under- 

 side shows most strongly the leaf-like ap- 

 pearance, the simia markings being almost 

 obliterated by brown, grey, or yellowish cloud- 

 ing, with midrib line distinct, forewings very 

 strongly falcate. 



