Dr. G. D. Hale Carpenter on Pseudacraea boisduvali. 649 
from Natal, Rhodesia, etc., show a white irradiation of 
the centre of the hind-wing, and this is also present in 
a certain number of the Pseudacraeas from the same 
localities. This white irradiation has been beautifully 
shown in Eltringham’s magnificently illustrated ‘‘ African 
Mimetic Butterflies,’ Oxford, 1910 (Plate 6). 
At Mombasa, in British East Africa, however, where the 
zetes are still of the Eastern form with a well-marked 
orange bar on the fore-wings, none of the Oxford specimens 
show the white irradiation, and neither do the boisduvali, 
save for the minutest trace along a few nervules, which is 
only visible on very close inspection, as in fig. 11, Plate 
XXXVII. In the photograph the white is more con- 
spicuous than in the actual specimen. 
Now let us turn to another point. The Western form 
of the male (which we may now call boisduvali boisduvali 
in contradistinction to the Eastern boisduvali trimenc), as 
illustrated by the two specimens in the Hope Department, 
shows, at the base of the fore-wings, a very marked suffusion 
with black, which replaces the red colour over approxi- 
mately the basal half of the wing. This is particularly 
well shown in the specimen from Sierra Leone (Plate 
XXXVII, fig. 2), but the other, from Angola (Hewitson, 
1873), which is in poor condition, does not show this so 
clearly. It may be remarked here that as we reach the 
more southern latitudes of the tropical West Coast an 
Eastern affinity begins to appear not only in Ps. boisduvali 
but in other species as well. The darkening of the fore- 
wing basal area is exactly the change most needed to 
produce a likeness to Acraea egina, which differs from 
A. zetes acara, amongst other less conspicuous points, in 
having the red colour on the fore-wing replaced by black 
over this very part of the surface. (Compare figs. 1 and 
10 on Plate XX XVII.) Now, out of the whole number of 
specimens of the East African male boisduvali trimeni in 
the Hope Department, only one, taken by the Rev. K. St. 
Aubyn Rogers near Mombasa, Dec. 29, 1906, shows this 
black suffusion over the base of the fore-wing at all well 
marked. This was described as an interesting link between 
trument and boisduvali proper by Trimen in an appendix 
to Rogers’ paper on the ‘‘ Bionomics of East African 
Butterflies ’’ in these Transactions, 1908, p. 552. But, on 
comparing the males from Uganda (8 from Bugalla Island 
and 2 from the mainland) one finds this basal black very 
