44 



likely that a single type, such as black and transparent, with a 

 blui.^h coloured wing membrane, would occur over the sreatei' 

 part of tropical America, and at a variety of elevations, if there 

 was not some common object to be attained. The other explanation 

 which would hold for the variously coloured groups is that 

 there is mimicry between them, the mimics being Miillerian in 

 their action. Some of the transparent Ithomiines, such as Thi/ridia 

 {Met/ionn) theinisto and Dircenna dern are very conspicuous sitting 

 in company with the Danaid Itiina ilione in S. Brazil on flowers of 

 Eiipatori 11)11. In the " Proceedings of the Entomological Society," 

 1912, p. xliv., I gave a note on the dissimilar habitats of different 

 Ithomiines and instanced this species in contrast with the smaller 

 black and transparent forest frequenting species, Pseudoscada ado.^a, 

 Pteronijnna ki/Icu and Hi/iiwnitis ,andnnnica form andania. The 

 Ithoiiiiiiiif, however, are never in my experience, to be found right away 

 from the shelter of the forest or patches of woodland. Their flight is 

 slow, and they keep near the ground just as some Helicouiia species 

 do. The nearest approach in flight amongst the British Lepidoptera 

 that I can think of is perhaps to be found in our winter species of 

 Geoinetridcc, Hi/beniia defoUaria, H. aurantiaria or (Jporabia dilutata, 

 but an even better illustration of the flight is to be found in the 

 dragonfly, Callofdenjx vin/o. Bates speaks of the flight of the 

 lthoi)iiin<ra.s slow and " that their structure is feeble and unfurnished 

 with apparent means of defence, and living in places which 

 are incessantly haunted by swarms of insectivorous birds." This 

 last observation coming from so experienced a naturalist 

 should carry great weight as to the distastefulness of the group 

 and pave the way for the acceptance of Bates' theory, that 

 these butterflies are mimicked by other butterflies that are not 

 distasteful. The particular mimicking butterflies that struck 

 Bates were the aberrant Pierines of the genus Dismorphia, or 

 as he called them the Leptalides, which w^ere found in company 

 with the Ithomiines, but not commonly. Haensch has observed 

 in Ecuador that the mimetic species of Disiiiorphia " such as 



D. arise, D. theono'e like the Ithomiids, etc are fond 



of the shades of the thick forest," and that "the bright coloured 

 species such as B. pra.riiur, ]>. (ntni/cha, etc., are also found in the 

 lighter places in the woods." These observations confirm my own 

 in Venezuela and Brazil. Although quite a number of Dis- 

 morphias seem to suggest a mimetic resemblance to the Itluniniiui' 

 there are very few cases where the resemblance is anything, except 

 a general likeness in outline and colour, without special detail. It 

 it is only with those species that are found regularly in the haunts 

 of the shade-loving Ithomiines that real resemblance is shown. 

 Such as D. )iielano'e with Ithomia nne<ia as observed by Bates, D. 

 metlujDina with Heteroscada nazoria, or D. pintlucus with Atria 

 enriiiiedia, in British Guiana. But before going into the mimicry 

 which surrounds the Itliumiina', and which is so extensive and forms 



