31 



Am. albimaculata, and the relatively very rare Am. grogani. 

 These butterflies, however, although as a whole a very important 

 element in the Danaine fauna, have not the conspicuous pattern 

 of Am. niavius, and it is to be observed here, as in other parts of 

 Africa, that when these two Danaine patterns exist side by side 

 the more conspicuous one exerts a far more powerful influence 

 upon the mimetic forms of dardaniis, even when the model which 

 bears it is not nearly so abundant as the others (cf. p. 34). 



We pass to the tropical west coast represented in the 

 seven drawers now placed in the frame. The northern section 

 is marked by the excessive predominance of hippocoon, corre- 

 sponding with the fact that, of the series of models mentioned in 

 the preceding paragraph, only niavius and chrysippus exist in 

 this part of the range. Furthermore, chrysippus is represented 

 by the tropical west coast form alcippus, with white hindwings, 

 and is therefore even less suitable than in other parts of Africa 

 as a model for dardanus. Along the whole of the tropical west 

 coast the strange ancestral form dionysus occurs in relatively 

 small numbers. This female possesses a primitive forewing 

 pattern much like that of trimeni. but it has entirely lost the 

 yellow ground-colour of the male, being white-marked like 

 hippocoon. The hindwing is yellow, resembling, but paler than, 

 that of the western trophoniits. The forewing pattern exhibits, 

 like trimeni, great variation in the development of the black bar 

 which originates the mimetic pattern. In some individuals it is 

 even more rudimentary, and therefore more like the Madagascar 

 female, than in any triineni that I have seen. 



We may feel confident that the results of breeding from a 

 female form in any locality may be fairly accurately predicted 

 by looking to the relative proportions of female forms which 

 there exist. For this reason I anticipated that the great majority 

 of families bred in the northern section of the west coast would 

 yield hippocoon and nothing else. Owing to the kindness of Mr. 

 W. A. Lamborn I have fortunately been able to test this con- 

 clusion, and the drawers before you contain three families bred 

 by him from hippocoon females, in the Lagos district. These 

 families contain respectively 14, 13, and 10 females, and all are 

 of the hippocoon form.^ 



^ Proc. Ent. Soc, Loud., 1912, pp. xii-xv^ii. Since the address was 



