304 Professor EK. B. Poulton on Mimetic Forms of 
spicuous in latifasciata, and this is well matched except 
in form by the mimic. In fresh specimens moreover the 
ground colour of both wings in the Toro model and mimic 
is of a distinctly brownish shade of black, wanting in the 
dark ground of the more eastern pair. The discal band 
of the hind-wing in ?. latifasciata (Plate XXII, Fig. 3) 
is fulvous and broader than the white band of quadri- 
color (Plate XXI, Fig. 3): the triangular basal brown 
patch of the hind-wing under-side is reproduced above 
in both species of Planema, but the black spots are indis- 
tinetly seen on the upper-side of latifasciata, while the 
chief members of the group are conspicuous, being in fact 
reproduced on the upper-side of qguadricolor. In toruna 
the discal patch on the hind-wing is fulvous, and the effect 
at a little distance is singularly like that of the model. 
It is however produced in a different way; for the uniform 
bright falvous tint of latifasciata is imitated by a fusion 
of two distinct colour elements in ¢orwna,—viz. the paler 
fulvous ground colour of the patch and the deep fulvous 
internervular and intracellular rays which traverse it. 
The shape of the discal patch has also been modified into 
close resemblance to the band of Jadifasciata, although a 
trace of the angle, so well known and conspicuous in the 
forms of johnsioni, remains as a guide, indicating the path 
of evolution. The basal invasion by deep rich brown of 
the pale patch on the hind-wing suggests the basal 
triangular area of the Planema model. On the under-side 
the patterns of both model and mimic are reproduced in 
paler shades, still maintaining their close resemblance. 
The discal pam of the hind- -wing of Planema and the 
corresponding patch of the Acreva. are white, and in the 
latter the characteristic squarish shape is far more 
prominent than on the upper-side. The basal spots of 
the hind-wing under-side which are so concentrated 
tewards the base in other forms of johnstoni are here 
moved outwards and are placed upon and along the 
borders of a rich brown triangular area resembling but 
much smaller than that of the model. The toruna form 
of johnstoni is one of the most interesting of the mimetic 
appearances developed by this remarkable and protean 
species. 
Acrea johnstoni, form fulvescens, Oberthiir (1. c., Pl. I, 
f. 21). This, the last of a wonderful series, is one of the 
most remarkable, the black ground colour persisting only as 
