108 Mr. G. A. K. Marshall on Diaposcmatism, with ref< rence 



divided into three sections. In the first, comprising only 

 the more primitive tclthusa, the sexes are alike, being 

 blackish, with white markings and an irroration of grey 

 scaling; the under-side having three red spots. In the 

 second the sexes are again alike, both being black, with a 

 red bar across the fore-wing and with a very striking 

 broad blue-grey suffusion over the bases of both wings ; 

 inferior red spots (two) present or absent. Finally, in the 

 third section, the sexes are different, the males being 

 blackish-brown with general grey irroration ; while the 

 females are brown, with a pink or red bar in the fore- 

 wing, having a basal grey suffusion in the former case, and 

 none in the latter; inferior red spots (two) present or 

 absent. There is obviously no mimicry of H. melpomenc 

 in the first section ; neither can its occurrence, so far 

 as concerns the upper-side, be reasonably claimed in 

 the second. For although the red bar in the fore-wing 

 may be urged as a mimetic character, this is rendered 

 highly improbable by the presence of the striking basal 

 pale marking, which, with the black ground-colour, gives 

 the insects a totally different appearance. It is only 

 in the third section that we find any real mimicry, 

 namely, in the females of charops, venezuelana and peru- 

 viana, the last two being probably only local races of the 

 first. These forms being brown and having lost all traces 

 of the pale suffusion, do very convincingly suggest the 

 existence of a close mimetic association with II. melpomenc. 

 Here, if anywhere, there should be evidence of reciprocal 

 mimicry ; but unfortunately for the hypothesis charops 

 happens to be one of the species of Pereute which does not 

 possess any red spots at all on the under-side, and this 

 fact alone renders it highly improbable that the spots of 

 melpomenc are diaposematic. It appears even open to 

 doubt whether they have any real mimetic value at all. 

 In Pereute they occur most markedly in the more 

 primitive, and apparently non-mimetic, telthusa, and yet 

 they have actually been lost in P. charops, although it 

 closely mimics a Hdiconius in which they are present. 

 How then can we consider that these spots are so 

 important that they have been modified in mclpomene 

 by the influence of the very different P. leucodrosime 

 (belonging to section 2), especially when it is noted that 

 they differ considerably both in number and position in 

 the two species ? Further, if their mimetic value is so 



