group of Butterflies, Potaro District, British Guiana. 419 
It appears evident from the specimens that the banding 
of the hind-wing and the presence of the red marks before 
the apex of fore-wing go together. It is also significant 
that these specimens have been secured in one or other 
of the two dry seasons. My own specimen, with an indi- 
cation of a band in the hind-wing, has also the red marks 
before apex and was taken on March 27th, 1905, the end 
of the short dry season. Professor E. B. Poulton’s banded 
specimen has also red marks before apex and was taken 
on August 28th, 1903, the early part of the long dry season, 
In view of the great interest attached to this species as 
to whether it is the centre of the association of the dark- 
ened hind-winged insects, it may be useful here to look at 
the range of the insect. From the limited material avail- 
able it seems certainly to be most plentiful in British 
Guiana. It occurs in the Berbice district adjoining 
Surinam, and from the only two specimens seen from 
there one shows a tendency to banding above and strongly 
below, the other is normal, both have indications of red 
apical marks on upper-side and strongly developed 
beneath. Six specimens originally in the Godman and 
Salvin collection now at South Kensington are labelled 
Roraima. This must mean somewhere in the Roraima 
district and not the mountain itself, which is bare rock 
and out of the Forest region. None of these six are at 
all banded, either above or below, and only one shows any 
apical marks, and that is only weakly and on the under- 
side. These six specimens are therefore interesting as 
suggesting a more extreme dark form away back in the 
interior of the country. A single specimen has the label 
“ Bartica,” a place 40 miles in from the mouth of the Esse- 
quibo, and I myself took it there, though only singly. 
The only locality outside of British Guiana that I have 
been able to discover is a specimen with a label “ Colombia,” 
which like the Roraima specimen is now in South Kensing- 
ton, but originally in the Godman and Salvin collection, 
Were it not that all insects in the latter collection have 
been set up and labelled with the greatest care one would 
be inclined to discredit the locality. The specimen is a 
very interesting one. It is strongly banded below, and 
both above and below has exceptionally strong red apica 
marks, 
Of the other two Melinxa species there is little variation 
to record. Melinza egina is extremely constant on the 
TRANS. ENT. SOC. LOND. 1906. PART III. (JAN. 1907) 28 
