120 Dr. H. Eltringham on Specific and 



most of the reputed species of the genus, from the point 

 of view of the structure of the male claspers. In a general 

 way the conclusions suggested show considerable and in 

 some cases remarkable correspondence with the order in 

 which the reputed species have been arranged in existing 

 works. Most of the forms which now appear conspecific 

 have already been placed together as nearly related. 



The question of the specific value of the genitalia is 

 difficult and complicated. The claspers have many forms, 

 showing that we are not dealing with a genus in which 

 these organs are of a primitive and simple character. The 

 highly modified form of the armatures in many species sup- 

 ports the view that specific identity alone accounts for the 

 resemblances found between the organs of forms hitherto 

 regarded as distinct. It will be interesting to see to what 

 extent external features help to confirm the conclusions 

 arrived at from anatomical study. 



The evidence of pattern and colour. 



In considering the question of pattern it is important 

 to distinguish between resemblance due to affinity and 

 that due to mimetic influences, and it is just on this point 

 that the evidence of the genitalia affords valuable clues. 

 Thus the resemblance between " silvana " ethra and 

 narcaea flavomaculatus would at first appear to support 

 the theory of the affinity of silvana and narcaea. We 

 have seen, however, that whilst on anatomical grounds 

 silvana and narcaea do appear to be conspecific, " silvana " 

 ethra is not to be regarded as a silvana at all. According 

 to Seitz, ethra and narcaea flavomaculatus fly together at 

 Bahia and are hardly distinguishable from one another. 

 This fact, coupled with the known anatomical difference, 

 points strongly to an instance of mimetic resemblance. 

 As is well known, most of the Silvaniformes are modified 

 to resemble Melinaeas and other butterflies of different 

 subfamilies. Whether in likeness to a common model or 

 to each other, several forms of the Silvaniformes bear 

 strong resemblance to other Silvaniformes. Thus — 



ethilla aerotome resembles pardalinus lucescens. 



anderida melicerta ,, " silvana " metaphorus. 



anderida zuleika ,, hecalisia octavia. 



anderida holocophora ,, numatus superioris 



(dark form). 



