notes on Butterflies from the Victoria Nyanza. 217 
from 7’. petiverana in the greater length of the fore wings 
and in the possession of pale sulphur-yellow areas at the base 
of the hind wings only interrupted by dark crossing nervures. 
M. formosa neumanni, Rothsch., from Abyssinia is of great 
interest, and differs in several significant particulars from 
typical formosa. 
These differential characters are— 
(a) Slightly shorter fore wings. 
(8) The presence of a V-shaped mark of pale yellow 
between the median nervure and first median 
nervule near their junction. 
(y) The brown colour of the fore wing 1s darker and 
less extensive. 
This latter characteristic has already been pointed out 
by Mr. Walter Rothschild, Nov. Zool. 1902, p. 596. 
The above characters are also of great interest in that 
they all of them show affinities to 7. limniace. B is 
especially characteristic of that species. 
Having therefore inquired somewhat into the ancestry 
of M. mercedonia and formosa it will be seen that their 
elongated fore wings and pale areas at the base of their 
hind wings are new developments and _ non-ancestral 
characters. These two points however are characteristic 
features not only of Papilio rex (in which they are 
specially marked) but of several other African “ Swallow- 
tails,” including P. leonidas itself, the mimic of 7’ 
petiverana. 
There can be little doubt therefore that the above- 
mentioned characters of these Danaines have been obtained 
from the Papilio. As regards the brown colour of both 
Papilio and Danaine, on the other hand, the Danaine has 
almost certainly been the model. In this matter we must 
remember that red or reddish-brown is very rare in 
African Papilios. It occurs in the trophonius 2 form of 
P. cenea and P. ridleyanus, White, both mimetic; also toa 
less extent in the golden-brown triangle at the base of the 
hind wing in the zenobia group of Papilios mentioned 
above. In Danaines, on the other hand, this colour is by 
no means uncommon, e.g. Limnas, Salatura and the allied 
genus Anosia. Further, as we have already seen, 7. 
petiverana (the probable ancestor of the two Danaines in 
question) exhibits a tendency to brownness as compared 
with its Oriental allies. It is also a significant fact that 
