Mimetic Relationships in the genus Heliconius. 105 



There may be something bo be said for this view, though it 

 will not explain further cases yet to be described. 



H. silvana, Cram. 



Of this form three subspecies are named, and though the 

 genitalia of (In 1 group are of little assistance in many of the 

 "I closer resemblance they seem to show that at least 

 three of the forms hitherto regarded as subspecies of 

 silvana do not belong to silvana at all, but to two other 

 species. On PI. XIII I have shown the claspers of two 

 specimens of silvana silvana taken at random. One is 

 hardly distinguishable from numatus guiensis, whilst the 

 other is but little modified from narcaea narcaea. A part 

 of the difference is due to the bending ewer of the apex of 

 the clasper, but this is not a point of great importance and 

 probably would not occur in a perfectly fresh specimen. 

 Now. silvana occurs in Guiana, Venezuela, N. Brazil and 

 Peru. The anatomy of the armature gives no reason to 

 suppose that it is anything but a form of numatus, just as 

 the hitter on the same grounds appears to be as closely 

 related to narcaea'. 



H. ethilla, Godt . 



Some twelve forms of this species have been named, 

 ranging through Trinidad, Guiana, Brazil, Venezuela, 

 ( 'olonibia, and Panama. Seven illust rat ions of the claspers 

 .ne given on PI. XIII. The two specimens of ethilla ethilla 

 are by no means identical, whilst the two of ethilla tyndar us 

 are markedly different. One example of ethilla ethilla 

 resembles narcaea satis and is not unlike numatus numatus. 

 The outline of ethilla aerotome is very different from one 

 example of ethilla ethilla, but not sufficiently distinct from 

 one of ethilla tyndarus. My friend Mr. W. J. Kaye. regards 

 ethilla as conspecific with numatus, a view I am strongly 

 inclined to support, further adding that so far a- the 

 armatures are concerned there is no more reason for 

 separating either from narcaea and silvana. 



H. gradatus, Weym. 



Of this rather rare species I have been able to make 

 only one preparation from its subspecies, thielei, Pill. As 

 will be seen from the illustration on PI. XI II, the clasper 



