536 Mr. H. W. Bates on Butterflies 
inhabiting the alluvial pla of the Amazons and its 
margins; the resemblance being greatest, as was na- 
turally to be expected, to the Parad productions, 
None of the peculiar forms of Southern or Middle Brazil 
are represented in the collection, although the physical 
features of the district more nearly resemble those of 
Brazil proper than the plain of the Amazons, and there is 
no known barrier to migration from the South. Some of 
the undescribed species (e. g. Heliconius paraplesius and 
Olina Stalachtoides) had been found long ago in the pro- 
vince of Para, by Mr. Wallace, probably on his excursion 
up the Capim river, which flows from the district of Montes 
Aureos. The new Hesperiide and Thecle will be described 
and figured by Mr. Hewitson, who is at present engaged 
on those groups. ‘wo other gentlemen engaged at the 
mines also formed collections, and whilst preparing this 
paper I have had an opportunity of seeing them ; they 
do not add much to Mr. Belt’s list of species, but amongst 
the additions are a fine Papilio, quite new to science, a 
new Callithomia, and an Ithomia (I. Hippodamia) interest- 
ing as being a Cayenne and Surinam species, not found 
in the intermediate valley of the Amazons. 
Before describing the new species, a few interesting 
facts in distribution and variation supplied by these col- 
lections merit a few words of notice :— 
Leptalis Theono? and Orise. 
In the midst of a series of IJthomiu Flora and its 
varieties, in Mr. Belt’s boxes, I detected four specimens 
of my old friend the mimicking Leptalis Theonoe ; and 
in the same way, amongst a fine set of Methona Psidi 
and Themisto, was a specimen of the still rarer Leptalis 
Orise. They had deceived the keen eyes of Mr. Belt, 
who, although no novice, for he had collected butterthes 
in other countries, and had given much attention to the 
varieties of Heliconiide, had not noticed any difference 
between these Leptalides and their associates. The occur- 
rence of these insects in this district is so far teresting, 
that it confirms the rule I have pointed out in the paper 
I have elsewhere published on the Heliconiide (Trans. 
Linn. Soc. xxiii. 495), namely, that the mimicking Lepta- 
lides are found only where the species of Heliconiide occur 
which they mimic, and become modified when their asse- 
ciates are replaced by other species or races, so as to 
