212 Mr. S. A. Neave: some bionomie 
the confluent edges of their distribution is of remarkable 
interest.* It should help to impress upon systematists 
the importance of carefully considering the question of 
geographical races of species before making new species 
on slight differences. ° 
Mimetic Groups wiItH DANAINE MODELS. 
The black and white Amauris niavius, Linn., forms the 
model for an important group of butterflies of many families. 
It is evidently very abundant on the shores of the Lake. 
There are 118 specimens in the Wiggins Collection. 
The group comprises :— 
Luralia anthedon, Doub. et Hew. (14). 
Aypolimnas monteironis, Druce (4 f g, 3 2 2), of which 
the 2 only is mimetic. 
Papilio dardanus &, f. hippocoon, Fabr. (8), mostly from 
the eastern side of the Lake. The f¢ ¢ of dardanus (46) 
were common nearly everywhere. 
Hlymnias bammakoo, Westw. (7), all from the Western 
districts. 
In all these forms the resemblance to the model is 
remarkably good, the distribution of white markings on a 
black or dusty ground faithfully follows those of the model 
and differs in much the same way from the South and Kast 
African mimics (HZ. wahlbergi, P. cenea, hippocoonotdes, etc.) 
of A. niavius dominicanus as the two models do from 
each other. 
The 2 2 of Planema godmani, Butler (2), with the recently 
described Pseudacrexa tirikensis, mihi (3), resembling it in 
an astonishing manner, form a subsidiary black and white 
group within the larger assembly having niavius as its 
model. This is, perhaps, especially the case when the 
insects are on the wing. At rest the Planema, and the 
Psendacrea closely following its model, present the 
character so common in the larger Ethiopian Acrxine 
of a black-spotted chocolate-brown triangle at the base of 
the hind wing on the under surface. The influence of this 
character on other forms and of other forms on it has 
* Professor Poulton has already called attention to the case of 
A. niavius in his Presidential Address to the Entomological Society 
1904, Trans. Ent. Soc. 1903, p. xciv. 
