( xxxiv ) 



Bourbon, at first suggested that the two species were not 

 nearly allied, and that their marked superficial resemblance 

 may have been due to mimicry. At the same time any 

 attempt to explain the growth of a mimetic likeness presented 

 the gravest difficulties. The details of the pattern of dume- 

 torum indicated close aflinity with the black and white NejJtis 

 saclava, Boisd., of Madagascar and the mainland of Africa; 

 while the much greater simplification, especially on the under 

 surface, oifrohenia, suggested affinity with the Austro-Malayan 

 species of the group of N. consimilis, Boisd. If this interpre- 

 tation were correct, frohenia would take its place beside the 

 s})ecies of Eujjloea as representatives of an Eastern butterfly 

 fauna. Mr. G. A. K. Marshall has, however, carefully 

 examined the neuration of these species, as well as N. 

 comorarum, Oberth., from the Comoros, and iV, 'nutyotlensis 

 from Mayotte, and has compared them in this respect with 

 saclava and consimilis. His results leave no doubt that, as 

 regards this important character, N. frohenia, as well as the 

 other three species of Neptis in the islands surrounding 

 Madagascar, is closely related to saclava and reraote from 

 consimilis. Mr. Marshall has kindly drawn up the following 

 account of the evidence of affinity based on neuration : — 



" Neptis frohenia, F., fi-om Mauritius, differs from the 

 superficially similar N. consimilis, Boisd., from the Austro- 

 INFalayan islands, and agrees with saclava, Boisd., in the 

 following neurational characters : — 



" In frohenia the origin of vein 10 of the fore-wing is much 

 nearer to apex of the cell, so that its distance from that point 

 on the distal side is approximately equal to the distance of 

 vein 11 from the same point on its proximal side. In the 

 hind-wing veins 6 and 7 are very close at their origin, and 

 vein 5 has a sharp curve at its base, representing a rudimentary 

 discocellular. 



" In consimilis the origin of vein 10 of the fore- wing is much 

 further removed fi-om the apex of the cell, its distance being 

 almost three times as gi-eat as that between vein 11 and the 

 same point. In the hind-wing veins 6 and 7 are appreciably 

 separated at their origin, while vein 5 is scarcely curved at the 

 base, giving the upper edge of the cell a much flatter outline. 



