248 PSEUDACRAEA EURYTUS 



purplish brown. Needless to say, this aposematic triangle 

 is a very marked feature in the model macarista. 



The shape of the orange bar crossing the fore wing 

 of hobleyi varies considerably, and in some cases bears 

 a resemblance to the rather dijfferent shape of the bar 

 in a very different species of Pseudacraea, namely, Ps. 

 kuenowi, which has the same general scheme of colouring. 

 It seems possible that these forms of hobleyi show the 

 secondary resemblance of one species to another, both, 

 however, mimicking the same model, which is found 

 and has been described by Dr. Dixey and Professor 

 Poulton in other combinations. It would be necessary, 

 however, before accepting this for a fact, to ascertain 

 whether the proportion of hobleyi with the bar like that 

 of kuenowi is greater in the areas where both are found 

 together than in areas where kuenowi does not occur. 



Another form of eurytus, described at the same time by 

 Neave as a different species, is a black and white female 

 known as tirikensis. Later this was found to be the 

 female of the male described as hobleyi, and the name 

 tirikensis fell into abeyance. Now, however, that both 

 are known to be not a distinct species but only forms of 

 eurytus, the name tirikensis again holds good as a mimetic 

 form name. This female form has a black ground ; on 

 the fore wing is a white bar bent at an angle, but the 

 posterior end of this beyond the elbow is often so suffused 

 with black as to reduce the bar to a large subapical area 

 only. Such a pattern very closely resembles that of the 

 female Planema macarista, also found in Uganda flying with 

 the mimic. The hind wing is black and white, and shows 

 well the umber triangle at the base on the under side as 

 in the model. (Plate I. figs. 7, 8.) 



This form is very variable, and graduates into others. 

 Thus a form from Gaboon, copying the female Planema 

 excisa, has the fore wings like those of tirikensis, but the 

 hinder end of the white bar is tinted dull yellow, and the 



