THE WOELD MODELS FOR MIMICRY 153 



lerian Mimicry is evident between the different 

 genera and sections of the specially protected 

 groups themselves. 



In the richest and most remarkable butterfly 

 fauna in the world, that of South America, the 

 dominant specially protected group is composed 

 of the Ithomiinae, allied to the Danainae, and 

 called by Bates * Danaoid Heliconidae '. Next in 

 importance come the Heliconinae, allied to the 

 Acraeinae, and called by Bates ' Acraeoid Heli- 

 conidae '. Both of these are extensively mimicked, 

 especially the Ithomiinae : in fact it was the close 

 and obvious Mimicry of these by certain species of 

 the Heliconinae that puzzled Bates and ultimately 

 received an interpretation in the Miillerian Hy- 

 pothesis. In addition to the above, this rich and 

 varied Region contains numerous true Acraeinae, 

 mimicked considerably, and a small number of 

 true Danaine species. These latter, which are of 

 extreme interest, fall into two groups. One of 

 them, the Lycoraeini, containing the two genera 

 Lycorea and Ituna, is confined to South America, 

 and bears evident traces of long residence in the 

 Region. The whole of the species are mimetic of 

 various dominant Ithomiine genera, while at the 

 same time some of them appear also to act as 

 models for other butterflies, in a single case 

 (Ituna phenarete) even for one of the rarer species 

 (Eutresis imitatrix) belonging to the Ithomiinae 

 themselves. It was the resemblance between 

 the Lycoraeine genus Ituna and the Ithomiine 



