562 Mr. Guy A. K. Marshall's 



contention, but bear out Mr. Butler's i-emark, that " it 

 does not follow, because a species does not vary in one 

 part of Africa, that it therefore shows equal constancy 

 in another part." In the warmer timbered coast belt 

 artaxia varies very little seasonally, but on the plateau 

 the variation is very marked. Mr. A. B. Koe, of Estcourt. 

 informs me that when on a shooting^ trip in Angoniland 

 (alt. circ. 4,000 ft.), near Lake Nyassa, he took P. 

 nachtigalii in considerable numbers in the end of 

 December, 1892, and they were then just emerging. 



Another genus presenting most interesting local 

 seasonal variation is Mycalesis, the winter forms in the 

 highlands of the interior being markedly different from 

 those of the coast region. In the Mazoe and Umfuli 

 districts of Mashunaland I captured Mycalesis simonsii, 

 Butl., and M. selonsi, Trim., very commonly during the 

 dry season, but they invariably disappeared as the rains 

 set in ; in fact, the former is only to be found among the 

 long withered grass with which its colouring harmonizes 

 so well. As I have always considered it to be an axiom 

 that in South Africa there is no such thing as a species 

 (in the true sense of the word) which is confined exclu- 

 sively to the dry season, I therefore proceeded to investi- 

 gate the case of simonsii and selousi, and I am now 

 convinced that they are respectively the dry season forms 

 of M. j)ers'picua, Trim., and M. sa.Jitza, Hew. 



Trimen has noted the close connection between 

 simonsii and pcrspicua, and, indeed, the underside of 

 the southern winter form of the latter is practically 

 indistinguishable from that of simonsii. Moreover, 

 towards the chano^e of seasons simonsii shows a strono; 

 tendency towards the upperside coloration of perspicua, 

 some specimens becoming daik grey in the costal and 

 apical area of forewings, with a paler grey tint partially 

 obscuring the remaining yellow of upperside. 



(6.) Such specimens also show a marked develop- 

 ment of the ocelli both above and below, I have 

 seen specimens of perspicua taken on the Shire 

 River by Mr. Koe, in June, 1892, and they are 

 similar to the Natal form. During the winter of 

 1893, when travelling from the Limpopo to Salisbury, 

 along the main Mashuna plateau, I never saw a 

 trace of simonsii, though when Mr. Koe went up to 

 Matabelelund next winter he observed it first as he 



