Pseudacrea pogger and Limnas chrysippus. 265 
is found, but in this whole series of seventeen specimens 
of pogget no individual shows any resemblance to dorippus : 
it is purely a mimic of chrysippus and shows no approach 
to dimorphism. This is explainable on the ground that it 
is found only where chrysippus is the largely predominant 
form, and, so far as is known, it does not occur in, or has 
not yet reached, the parts where dorippus is relatively 
abundant—that is, the desert strip along the E. Coast, 
extending in the E, African Protectorate inland at least to 
the shores of Victoria Nyanza. In this respect it com- 
pares in an interesting manner with misippus ¥, of which 
the maria form, mimicking dorippus, is found all over 
Africa (Trans. Ent. Soc. Lond., 1902, pp. 473-484): and 
also with Acrwa encedon, L., var. daira, G. and S., which 
is only frequent in localities where its type dorippus is 
predominant (I. c. pp. 473-484). 
This occurrence in considerable numbers of what has 
hitherto been regarded as the rarest species of Pseudacrva 
supports the hypothesis that the mimics of this group are 
Miillerian rather than Batesian. This has already been 
argued for H. misippus (cf. Rep. Amer. Assoc. Adv. Sci.— 
Detroit, 1897; and Trans. Ent. Soc. Lond., 1902, pp. 480 
and 483, with references) as well as for the genus Psewda- 
crea and for A. encedon (pp. 480, ete.). The fact that 
the latter species, belonging to a protected and much- 
mimicked subfamily, is far more coincident geographically 
with the corresponding forms of its model H. mzsippus 
2 is obviously a powerful argument in favour of the 
Miillerian interpretation. 
Note By PRoressor E, B. Pouuton, F.R.S. 
Ir is deeply interesting to compare the details of the 
mimetic resemblance borne by Pseudacrea pogget to 
Limnas chrysippus with those of the other great Nympha- 
line mimic—Hypolimnas misippus 9. Almost all the 
pots in the following statement can be verified by 
means of the half-tone reproductions of the three species 
on the accompanying Plate XIV. It is to be observed, 
however, that Fig. 1 represents a 2 chrysippus with five 
wings, a second smaller left hind-wing concealing the 
central portion of the normal hind-wing of the same side. 
