Papilio dardanus (mcrojje) and Acr/ca jolinstoni. 297 



forms. Every one of the six 'polyiAxrpli'US cenca which 

 have come under my observation are primitive in the tint 

 of the pale markings and we mu.st assume tliat in this 

 case we are in presence of a truly ancestral feature. 



(Q An interesting gynandromorpliic spcciiiicn of the $ f 

 planemoides. 



Although the male and the diverse female forms of tlio 

 southern P. dardanus — the sub-species cenea — have been 

 shown by direct evidence to be a single species by the 

 important breeding experiments of Mr. G. F. Leigh, F.E.S.,*' 

 the same proof is unfortunately still wanting in other 

 parts of Africa. It is therefore very satisfactory that other 

 evidence has become available in the case of the most 

 recently discovered form 2^f'<^(ncmoides. This is in part 

 supplied by the existence of intermediates between it and 

 the other female forms of dardanus, two of which are 

 shown on Figs. 1 and 3 on Plate XX. But still more 

 striking evidence is supplied by a remarkable gynandro- 

 morphic specimen collected by Mr. T. T. Behrens, E..E., 

 and represented on Plate XVIII, Fig. 4. The butterfly 

 was obtained in 1902-3 on the west shore of the Victoria 

 Nyanza between Entebbe and the mouth of the Kageru 

 River. The admixture of male colouring, which is con- 

 fined to the left wings, is very well represented in the 

 figure, except upon the white patch of the hind-wing, where 

 the pale yellow streaks could not be ditferentiated from 

 the white background by photographic means. If the 

 black ground colour of the left hind-wing be compared 

 with that of the right, it is seen that three submarginal 

 irregular areas of a deeper shade are present on the former 

 wing but absent from the latter. These represent the sub- 

 marginal band of the male while the spaces between them 

 are the costal and inner gaps. The yellow male scales 

 pass through the costal gap as an almost continuous 

 streak, while they are developed in small scattered masses 

 in the neighbourhood of the inner gap. The yellow 

 scales reach the extreme margin of the hind-wing in the 

 concavities of the scalloped border, as in the male, while 

 the yellow of the two concavities nearest the anal angle 



* Published in Trans. Ent. Soc. 1904, p. G77, and in tlie present 

 memoir. 



