group of Butterflies, Potaro District, British Guiana, 425 
The solitary specimen with three red markings has them 
well developed. The specimen is a 9, and has the more 
usual rounded black area to the hind-wing, and it was 
captured on July 19th, 1904—the height of the rainy 
season. 
Heliconius silvana—tThe four specimens of this species 
are of remarkable interest. Two of them bear the usual 
pattern of black marking on the hind-wing while two 
show the black area divided by the ground colour, one 
being a good intermediate. Not one of the four have the 
white marginal spots developed. The species undoubtedly 
shows the strong local influence of its relatives, and 
especially is this to be noted in the two specimens with 
a banded hind-wing, these conforming with the predomi- 
nant forms of Melinwa mneme and Heliconius numata. 
These banded H. silvana, although rare, have been re- 
corded elsewhere. There are two such specimens in the 
Hewitson collection at South Kensington. One labelled 
Upper Amazon, and another a much smaller specimen, 
but more completely banded, from Para. The species is 
evidently on one of the limits of its distribution or would 
surely be commoner, especially as elsewhere, such as at 
Para, it is a very common and plentiful insect. 
Heliconius ewcoma—A single specimen was secured by 
Mr. C. B. Roberts in 1902. It differs in no way from the 
type, and is a mere accidental visitor, apparently to the 
Potaro region. The home of the species is on the Lower 
Amazon. The species readily fits in with the group 
through the more extremely banded forms of Heliconius 
numata. 
HELICONINE, Genus Hueides. 
Three species of Lweides have occurred, Hueides isabella, 
Eueides vibilia, and Eucides nigrofulva.* The two former 
only singly and the last not uncommonly. It is curious 
that one of the single specimens (that of ZH. isabella) is a 
common species, while the only species that has occurred 
at all frequently was found to be an undescribed species. 
It is this new species that conforms to a considerable 
extent to the main group, while Z. isabella (as far as can 
be ascertained from a single individual) is of the ordinary 
* Vide Ent. 1906, p. 52. Three other species of Hueides have 
occurred belonging to another small family group, H. lybia, £. 
aliphera, and HE. unifasciatus (?). 
