Users may be interested in a recently posted copy of F. Müller. 1879. Ituna and Thyridia; a remarkable case of mimicry in butterflies. Transactions of the Entomological Society of London, 1879, xx-xxix (transl. by Ralph Meldola from the original German article in Kosmos, May 1879, p. 100). It’s available at: http://www.ucl.ac.uk/taxome/lit/muller_1879.pdf