( ^li ) 



on p, vi that Libythea cinyras, Trim., is a mimic of JVeptis 

 frohenia be sound, it would support the conclusion that the 

 tawny markings are of great age. 



h. Changes Subsequent to Isolation. — Although it is 

 evident that the two north-western species are specially 

 related together, and the two eastern species also specially 

 related, so that they represent two distinct emigrations from 

 Madagascar, it is nevertheless true that more complete and 

 probably far longer isolation in the outermost island has 

 been followed by certain changes which have much' in common 

 on the two sides. In some characters the north-westernmost 

 N. coxinrarum differs from A^. mayottensis in much the same 

 way that the easternmost frobenia differs from dumetorum. 

 Both east and west of Madagascar the more remote and 

 isolated species has undergone simplification in the details of 

 pattern nnd outline, shown in a reduction of the undulations 

 of the outline, the comparative obscurity of the marginal and 

 submarginal pattern, and in the loss or faint development of 

 minute details in the pattern of both surfaces, especially the 

 under. This last effect is far more evident in frohenia. In 

 one feature, however, the upper surface of comoramm departs 

 further from mayottensis than fi^ohenia from dumetoruyn, viz. 

 in the loss of the mark on the inner margin which, in other 

 species of the saclava group, prolongs the band of the hind- 

 on to the fore-wing. This is an isolated feature ; for in the 

 retention of minute white points in the cell of the fore-wing 

 upper surface and in the whole pattern of the under surface, 

 comorart(,m is immensely nearer the saclava group than 

 frohenia or even chmietortimi. 



The pronounced simplification which has occurred in the 

 two most isolated species has been accompanied by a remai'k- 

 able persistence in the larger and more conspicuous elements 

 of the pattern, so that during flight or at rest with wings 

 expanded, y^^oSew/rt, at a little distance, would closely resemble 

 ihimetorum, and comorarum, under similar circumstances, 

 7)iayottensis. 



Such are the changes which have taken place in the two 

 most isolated species of this group of Nej^tis, and it is im- 

 portaut to separate sharply the reraai^kable and interesting 



