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XXXIV. On a Species of Moth found inhabiting the Galls of a Plant near to Monte 
Video. By Joun Curtis, Esq., F.L.S., $c. Communicated by the Secretary. 
Read February 10, 1835. 
IT AM induced to lay the following observations and the accompanying drawing before ~ 
the Society, rather with a desire of drawing the attention of those naturalists to the 
subject who may visit the country from whence the materials were brought, than with 
any hope of being able to explain the remarkable facts connected with the ceconomy of 
the insect which is the object of these investigations. 
Mr. Howship, who first showed me the curious galls and presented me with speci- 
mens, informed me at the same time that they were collected by Mr. Earle, who accom- 
panied Captain Fitzroy in the Beagle gun-brig: he found them, I understand, in De- 
cember, on a spot fifteen miles to the west of Monte Video, Rio de la Plata. The plant 
bearing the galls, which Mr. David Don thinks may be a species of Celastrus, forms a 
sort of underwood shrub, observed only in that part of the country. 
The branch represented at B (Plate XL.) shows the situation of two galls: they are 
frequently smaller, and sometimes five or six are clustered together, but I have never 
seen more than two issuing from the same point. Those in the plate are wrinkled, 
owing, I suspect, to their having been in a young state when gathered, for many of the 
examples are smooth. The galls arise where the attachment of leaves or flowers is in- 
dicated, and are therefore most probably produced by the transformation of the buds 
themselves. On the side of the gall is a round aperture, with an operculum beautifully 
fitted to it, (Fig. B., 0.) which may be easily picked out with the point of a penknife : 
this operculum is equally convex with the rest of the gall and is of the same thickness 
with it, but the diameter of the inside is less than that of the external surface, which 
forms a broader rim (Fig. 12, 0.). In Fig. 11. the operculum has been removed to 
show the orifice, round which the margin is thickened and a little raised. At Fig. 13. 
a gall is divided longitudinally, showing its texture and the internal cavity, with the 
aperture on the opposite side, from which the operculum has been removed. At Fig. 14. 
another section is given to show the situation of a pupa that is attached by its tail to 
the base, with its head close to the operculum, which of course gives way by a slight 
expansion or elongation of the pupa when the insect is ready to hatch, and the skin is 
then left sticking in the passage. 
Having explained the structure of these galls, it is necessary to observe that many 
insects belonging to the order Hymenoptera have the power of forming these excrescences ; 
one of which, the Diplolepis Galle-tinctorie, is well known as the fly causing the galls 
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