504 
W 
the normal facies of the genus or family to which they severally belong*. The re- 
semblance is so close, that it is only after long practice that the true can be distinguished 
from the counterfeit, when on the wing in their native forests. I was never able to 
distinguish the Leptalides from the species they imitated, although they belong to a 
family totally different in structure and metamorphosis from the Heliconidce, without 
examining them closely after capture. They fly in the same parts of the forest, and 
generally in company with the species they mimic. 
I have already given an account of the local modifications to which the Heliconidce are 
subject. It is a most curious circumstance, that corresponding races or species of counter- 
feiting groups accompany these local forms. In some cases I found proof that such species 
are modified from place to place to suit the peculiar forms of Heliconidce there stationed. 
As this is an important point, and one which throws light on the origin of mimetic species, 
I must ask the reader's careful attention to the details, referring to the plates. 
Plate LV. fig. 1 a (Ithomia Flora) and fig. 1 {Leptalis Theonoe) represent a Heliconide 
and its imitator, both of which inhabit the banks of the Cupari, a river belonging to the 
Amazon system, in 55° W. long. Neither of these is found on the Upper Amazons 
(60° to 70° W. long.), where I made the remaining part of my observations on these 
insects. At Ega, on this upper river, in 65° W. long., two species of Ithomia occurred, 
which I consider to be local varieties or races of I. Flora, namely, I. Onega (PL LV. 
fig. 2 a) and I. Illinissa (PI. LV. fig. 6 a). It is immaterial to the question in hand 
whether these be considered absolutely distinct species or races ; the Leptalis which 
was found in their company was the form called L. Lysinoe (PI. LV. fig. 3), with its ad- 
mitted varieties (figs. 4, 5, 6, and 8). Only one of these varieties of Leptalis mimics 
an Ithomia ; this is our fig. 6, which evidently counterfeits Ithomia Illinissa (fig. 6 a) . 
The prevailing form of Leptalis, the L. Lysinoe (fig. 3), has no resemblance to any 
Ithomia of Ega, but is, when flying, a wonderful imitation of the Stalachtis Duvalii 
(PI. LV. fig. 3 a), a common insect belonging to a genus (family Frycinidce) equally 
flourishing and abundant in individuals with the members of the family Heliconid<e. I 
think there will be no doubt in the mind of any one that the Ega Leptalides are local 
varieties of the Cupari L. Theonoe (fig. 1), when all the connecting links between them are 
studied in the figures given on our two plates. It is highly probable, therefore, that 
this species has been by some means modified with especial reference to the changed 
Ithomia, or other insects, of the locality. The varieties, figs. 4, 5, and 8, were excessively 
rare : they have the appearance of sports, and show how variable the species has been in 
this district. 
The same takes place at St. Paulo, in 69° W. long. Here we find the Ithomia again 
changed. Neither the I Flora of the Cupari and Lower Amazons nor the I. Illinissa of 
Ega occurs ; but the second Ega species, I. Onega, inhabits the district, and several other 
species not found in other places, amongst them I. Ilerdina (PL LVI. fig. 4 a), I Chryso- 
donia (PL LVI. fig. 3 a), and I. Virginia (PL LVI. fig. 6 a). The prevailing species of 
^ 
usual form of the family Pieridce, to which the genus Le^ 
mimetic species, totally unlike, as far as facies is concerned 
Nehemia 
