Pcqnlio dardanus (incrojm) and Acra^a johnstoni. 303 



jiale buff. The resemblance of this striking and beautiful 

 form is also promoted by its size ; for it is one of the 

 largest specimens of johnstoni which I have ever seen. 

 As in so many other cases this mimic is an even closer 

 approach to a co-mimic than it is to the primary model. 

 And of all the species which are grouped round Plancma 

 iwggci there can be no doubt that its resemblance is 

 strongest to the planemoidcs female of Paipilio dardanus 

 (Plate XX, Figs. 2, 4). I do not know of this latter from 

 Taveta where the {fi) form of scmifulvescens was collected 

 by Mr. St. Aubyn Rogers ; but plancmoidcs exists in the 

 A. H. Harrison collection from Nairobi, so that its exist- 

 ence in the neighbovirhood of Kilimanjaro and Taveta is 

 at any rate probable ; and the same may be said of 

 Planema jjoggei, the primary model, also labelled Nairobi 

 in the same collection. 



In both (a) and (/3) sub-forms of scmifulvescens the fulvous 

 part of the fore-wing under-side would be hidden by the 

 hind in the attitude of prolonged rest, so that the appear- 

 ence becomes synaposematic with many of the smaller 

 Acrieinm rather than with the particular Planema models. 

 On the other hand, in flight and probably during brief 

 rest between successive flights the basal part of the fore- 

 wing under-side would contribute to the visible appearance 

 and serve to reinforce the resemblance to the Planemas. 



(y) The third sub-form of scmifulvescens is the toruna 

 form (Plate XXTI, Fig. 3«), described under that name 

 from Toro, W. Uganda, by Mr. H. Grose-Smith. There 

 can be no doubt I think that this is a further develop- 

 ment of the form described by Oberthiir from Kilimanjaro 

 — a modification brought about by mimetic resemblance 

 to another Planema model, — P. latifaseiata, E. M. Sharpe 

 (Plate XXII, Fig. 3). It is altogether a much more perfect 

 mimic of this Planema than scmifnlvcsccns (a) is of the 

 allied P. quadricolor. The rich brown colour of the basal 

 half of the fore-wing is here ahke in model and mimic, 

 while the zigzag row of four spots tend in torv.na to fuse 

 and generally completely fuse into a zigzag fulvous band 



somewhat resembling but more irregular than that of the 



I'll 

 Plancma model. In P. latifaseiata the black inner border 



of the fulvous band is far more feebly developed than in 



P. qnadricolor, so that the absence of this border in toruna 



does not greatly detract from the likeness. On the other 



hand, the fulvous band itself is far wider and more con- 



