551 
W 
3. The black central stripe of the hind wing rnns from the middle of the abdominal 
edge to the apex of the wing. 
4 The pale snbmarginal spots of the upper surface are wanting. 
It is curious that these points of difference between H. Numata and H. Sylvana are 
almost precisely the same as those which distinguish Melincea Mneme from M. Egina. 
I judge from this that a mimetic resemblance is intended between the Heliconii and 
the Melincece — H. Numiata and M. Mneme, H. Sylvana and M. Egina, — the Heliconine 
insects being adapted to the Danaine species. If we trace the species or races allied to 
H. Numata over the whole of Tropical America, we shall find that each one mimics a 
Danaine species in its locality ; and I think it probable that they are all of the same stock 
as H. Numata. Thus, in Eastern Brazil H. Ethra mimics Mechanitis Nesaa ; and in the 
southern parts of the same country, H. Eucrate precisely imitates Mechanitis Lysimnia. 
I have already mentioned these and other cases occurring in New Granada, Nicaragua, 
Eastern Peru, and the Upper Amazons : the Heliconii are adapted sometimes to a Me- 
chanitis, and sometimes to a Melincea. 
H. Numata varies in structure as well as in colours. The wings are sometimes broader, 
sometimes narrower ; and their edges are simple in some examples, and festooned in others. 
The yellow crossbelt is sometimes blended with the ground-colour of the wing ; in many 
examples which connect the species with H. Eucoma it is narrow, and in others very 
broad, as represented in Cramer's figure. 
The central black stripe of the hind wing is often very broad, covering part of the cell ; 
at other times it is very narrow, and passes much behind the cell. 
The species is found abundantly throughout the Amazon region ; it occurs in thinned 
parts of the forest, where it is seen sporting about by twos and threes in the sunlight, or 
floating lazily in the air. The following is a remarkable variety occurring only on the 
Upper Amazons. 
Var. H. Isabellinus. 
S 2 similar in shape and in the position of the black markings to H. Numata. Pale 
orange-tawny ; in the fore wing the two macular belts, which in H. Numata are distinct 
and of a yellow colour, are blended together and of the same pale orange-tawny hue as 
the rest of the wing ; the nervures, at the point where the two belts touch, are margined 
with blackish ; the apical part of the wing is black, as usual, and is crossed by a row of 
four pale spots. 
Two examples occurred, one at St. Paulo, and one (much smaller) at Tunantins. 
3. Heliconius Eucoma, Hiibner. 
D 
577, 578 
This species differs from H. Numata in the yellow crossbelt of the fore wing being 
narrow and submacular, consisting of four or five more or less distinct elongate spots, 
and also by its being separated from the cell by a series of black spots, more or less joined 
together in the form of an oblique belt. It is, however, extremely variable. At St. 
Paulo and other stations on the Upper Amazons, many examples occurred of a very dark 
