Papilio dardanus (merope) and Acrea johnstoni. 293 
johnstoni, undoubtedly mimetic in this respect, we meet 
with a still further exaggeration of the same character, the 
outer corner of the square being pulled out so as to form 
the most distinctive feature of the wing (see Plate X XI, 
Figs. 1), 3a, and 4a, Plate XXII, Figs. la and 2a). That 
diaposematic resemblance is apt to arise between the Papi- 
lionide and the most distasteful groups in the same region 
has been shown by Dr. F. A. Dixey (Trans. Ent. Soc. 
Lond. 1896, p. 75; also 1894, p. 298) as regards 8. America, 
and recently in a very striking manner by Mr. S. A. Neave 
(Trans. Ent. Soc. Lond. 1906, pp. 216-218) as regards 
certain other African species. 
(4) Planemoides. Until Mr. C. A. Wiggins presented 
his splendid series of captures made in 1903 near the N.E. 
and N.W. shores of Lake Victoria Nyanza, there only 
existed in the Hope Department a single specimen labelled 
“Angola; Rogers, 1873.” This specimen was, as far as I 
am aware, up to 1903, the unique representative of 
planemoides in European collections. There are at the 
present moment no less than ten examples of the form, 
or of intermediates between it and other forms, at 
Oxford,* so that it is now possible to compare planemoides 
with the other mimetic females of dardanus and to 
attempt to assign its place and suggest its past history. 
It is convenient first to describe the intermediate 
specimens. 
(a) 2 form intermediate between cenea and planemoides. 
The specimen here described is represented on Plate 
XX, Fig.1. The discal patch of the hind-wing is not white 
as in planemoides but nearer to the buff of cenea, although 
with a faintly reddish-brown tinge which may perhaps 
indicate some influence of trophonius, The submarginal 
light spots are more developed than is usual in planemoides, 
although the example represented in Fig. 4 does not 
differ wideiy in this respect. While the hind-wings more 
nearly resemble the ¢ f. cenea, the fore-wings are on the 
fo) 
whole much nearer to planemoides, as may be inferred by 
* Some of these do not belong to the Hope Collection, but are the 
property of Mr. A. H. Harrison. They are however available for 
study and comparison, and two of them are represented on Plate 
XX, Figs. 1, 4. No less than five out of the ten examples are 
figured on the plates accompanying the present memoir, and a sixth 
by Mr. 8. A. Neave on Plate X, Fig. &. 
