652 Dr. G. D. Hale Carpenter on Pseudacraea boisduvalt. 
A. zetes, at any rate as far as the ¢ is concerned, that sex 
having a red patch along outer portion of inner margin 
of fore-wing, just as in egina 3, and larger than is exhibited 
by zetes 3, while in hind-wing larger black spots characterise 
both egina and boisduvaliz. On the other hand, as regards 
the presence of red spots in the hind-marginal border of 
hind-wing, boisduvaliz resembles zetes and not egina.” 
Prof. Poulton alludes to this curious changing of re- 
semblance to another model on the West Coast, in a note 
to Rogers’ account of Ps. trimeni, as follows (I. ¢., p. 528) :— 
“There can be no doubt that the eastern sub-species 
trimenii, with its conspicuous subapical yellow-ochreous 
fore-wing bar, mimics Acraea acara (in which the apical 
portion of the fore-wing is warm reddish-ochre), and bears 
no very close resemblance to areca or to any of the other 
large red black-marked, eastern Acraeas. The western 
boisduvalii, on the other hand, is a much closer mimic of 
Acraea egina, the western representative of areca, than it 
is of zetes, the representative of the eastern model of 
tromenw. This is all the more remarkable because zetes 
is replaced by acara in the Cameroons, as I was astonished 
to find in the collection of the Brussels Museum. 
“This mimetic relationship is unusual, and is all the 
more remarkable because the eastern mimic is transitional 
into the western, the eastern model into the western zetes, 
the western model into the eastern egina.” 
The mimetic resemblance of the female Pseudacraea bois- 
duvaliIt is the mimicry by the Bugalla Isle female 
which finally clinches the evidence that the Western 
Pseudacraea boisduvali mimics Acraea egina; for there 
exists on the island a peculiar variety of female egina, 
which is evidently drawing the local female Pseudacraea 
towards itself. 
This island female of A. egina, named alba by Eltringham 
(Trans. Ent. Soc., 1913, p. 412), approaches very closely 
to the subspecies medea of Cramer, which is also an island 
form and at present only known from Prince’s Island in 
the Gulf of Guinea. The female medea, Cram., is dull 
white with all the spots very large and prominent (Plate 
XXXVIII, fig. 5) 
The Bugalla females of egina (figs. 3 and 4) only differ 
from medea in that the hind-wings are not so white but 
exhibit a very slight brownish tint, so that they are to 
some extent intermediate between the typical egina and 
