of the genus Huchroma. 293 
less dense; the female has, at the apex of the fifth 
ventral segment, a very slight emargination, a mere 
interruption of the outline. As the coppery colour 
of the wing-cases fades away, the form becomes of darker 
and more obscure colour, and it is, I believe, such dark 
specimens that are usually found at Rio de Janeiro, and 
in the females of these dark coloured specimens the 
minute notch of the fifth ventral segment becomes rather 
deeper and more definite. 
The second form of B. gigantea differs from the 
preceding one in that the discoidal patches of the thorax 
are very conspicuous, but less shining than in the pre- 
ceding one, and are surrounded by avery distinct coppery 
rim, inside the greener margins, and the punctuation 
of the thorax is a little less fine; the copper colour of 
the upper surface is very predominant, the general form 
is a little shorter and broader, and in the female, the 
notch on the fifth ventral segment is comparatively deep 
and conspicuous. I have a pair of this form from Para 
on the Amazons, and a specimen sent me by H. Deyrolle 
with the locality Bogota (which is, however, I believe, 
incorrect). M. Deyrolle informed me that he had four 
other perfectly similar individuals of this form, and 
suggested that they were hybrids between B. gigantea 
and B. goliath. Although this form is that which in 
appearance and sculpture most resembles B. goliath, I 
see no reason at all to suppose the slight approximation 
to be the result of hybridisation, for in the more im- 
portant characters there is no approach made to B. 
goliath. 
The third form is remarkable by its colour, and by the 
very indefinite, almost entirely absent, discoidal patches 
of the prothorax ; the colour is dark, but changes a good 
deal, according to the direction in which the specimen 
is viewed, from a dark purplish copper to a dark green. 
The upper surface of the prothorax is very polished and 
shining, and the punctuation is very much reduced, and 
there is little or no pubescence; on careful examination, 
however, the marginal punctuation is clearly seen to be 
present. The notch at the apex of the fifth ventral 
segment in the female is broad and shallow. This is the 
form that is most dissimilar from B. goliath, and it has 
been sent in numbers from Georgetown, Demerara, by 
the Rev. W. Harper. It is not, however, the only variety 
found in Demerara. The native Indians of that part of 
