48 



AFRICAN MIMETIC BUTTERFLIES 



In the * Transactions of the Entomological Society ', 1906, an exhaustive paper was 

 published by Professor Poulton, on the forms of P. dardanus and Acraea johnstoni. There 

 all the forms of lycoa, johnstoni, and fallax were fully dealt with, careful comparison being 

 made of all the modifications geographically considered. The main conclusion was that 

 they must all be regarded as specifically identical with the western lycoa. This species 

 I have not figured, but it may be described as follows : — 



The male is about the size of Fig. 23, Plate III. The ground-colour is pale umber-brown, 

 somewhat redder in the hind- wings, and all the wings are more or less translucent. In the 

 fore- wings there is a sub-apical bar of a much paler colour, separated into four spots by the 

 intervening nervules, the first spot being a mere line between the first and second subcostals, 

 the second, third, and fourth, much larger, and occupying the whole internervular space, 

 and the fourth somewhat ovate, more distally placed than the rest, and nearly reaching the 

 hind-margin. Between the first and second median a large pale mark well defined basally, 

 but suffused towards the hind-margin. Beneath the first median another rather smaller mark, 

 more distally placed, and nearly reaching the hind-margin. The hind-wing pale discally, and 

 slightly suffused with brown towards the margin. Nervules and rays strongly marked. 

 Several small black spots at the base and a black line in the cell. Body black above, orange 

 beneath, and ringed and spotted with orange. In some examples the male is so nearly 

 transparent as to have almost lost the pale spots in the fore-wing. The female is slightly 

 larger and much blacker. The spots on the fore-wing are white, and there is a distinct 

 white suffusion beneath the base of the second subcostal, making the sub-apical bar more 

 continuous. The hind-wings are white with a broad blackish border extending to midway 

 between the hind-margin and the end of the cell. About the anal angle and the inner-margin 

 there is a slight reddish-brown suffusion, representing the reddish-brown colour in the male 

 hind- wing. The base is powdered with brownish black, and bears a few small black spots. 



The larva and pupa of Acraea lycoa are thus described by Professor Aurivillius ^ : — 



' Larva. Yellowish without markings, head and spines black. The spines are scarcely 

 as long as the diameter of the body.' 



' Pupa with usual black markings ; the black spots of the abdomen have pale centres 

 and are irregularly angular ; the abdominal segments 2-4 are armed with two short black 

 spines yellow at the base.' 



I propose to deal with Acraea lycoa and Acraea johnstoni together, as the similarity 

 between the fallax form of lycoa and the confusa form of johnstoni have led to some con- 

 fusion in nomenclature, and the present description of the forms will serve to explain some 

 of the features whereby the two species may be distinguished. As already stated, Professor 

 Poulton was led to believe, from an examination of the outward characteristics, that lycoa 

 and johnstoni gradually merged one into the other, and were in fact conspecific. It was 

 at his suggestion that I undertook a microscopical examination of the more minute structure 

 of the insects in question, with the result that lycoa, with its forms fallax and aeqiialis, were 

 found to be geographical races of one species, whilst johnstoni and its varieties, including the 

 Acraea toruna of Grose-Smith, were found to be also conspecific though distinct from lycoa. 

 Our present concern being with mimetic associations, I do not propose here to enter into the 

 details of this systematic inquiry,^ but must confine myself to a brief account of the peculiar 

 modifications which the patterns of these butterflies undergo. The mimetic relations 

 of these varieties have already been described by Professor Poulton (1. c). In West Africa 



1 Ent. Tidskr., xiv, p. 278, pi. 5, ff. 2, 2a, 2b (1893). 



2 A paper dealing with the subject at some length is in course of preparation. 



