548 PROCEEDINGS OF SECTION D. 
obvious that the form of the inflorescence is not reliable as a 
specific character. Bentham, however, says, “These peduncles 
with their umbels are, in their general arrangement, of some 
importance, constituting three types—(1) axillary or lateral, that 
is, solitary in the axils of the leaves or along the branches above 
or below the leaves ; (2) several together in short simple panicles 
at the end of the branchlet or in the axil of the leaves; (3) ina 
compound terminal corymbose panicle ; but these forms appear to 
pass into each other very much in imperfect specimens.” 
Useful specific characters are derived from the transverse outline 
of the peduncle or pedicel, such as terete, angular, compressed or 
winged ; and in a few species the pedicels are abbreviated, as in 
L, capitellata, which distinguishes it from 2. macrorrhyncha, both 
having fruits of the same shape. 
GALLS. 
“ Mr. Bauerlen informs the author of his belief that species of 
Eucalyptus can be unerringly determined by means of the leaf- 
galls.”’—Maiden, “ Useful Plants,” p. 428, 1889. Mr. Froggatt, 
Proc. Linn. Soc., 2nd ser., vol. vii, p. 353, in the Notes on the 
Brachyscelide, which form woody galls on the twigs, leaves, and 
deforming the flower-buds, has, however, stated that ‘The mem- 
bers of the genus Brachyscelis are distinctly Australian, confining 
their attacks to the Eucalypts, and at one time I believed that 
each species of coccid had a partiality for a particular species of 
Eucalyptus ; but observations extending over several years have 
proved that, though some of the rarer species may keep to one 
tree, most of them thrive on various Eucalypts.” 
FLOWER-BUD. 
The operculum offers considerable diversity of form, and so far 
as I know it is very true of the species. It was first employed as 
a basis of classification by Willdenow, Sp. Plant., 1799, who 
grouped the twelve species then known into two sections according 
as the operculum was conical or hemispherical. 
Don, 1832, also used the operculum in his subdivision of the 
species with alternate leaves. He recognised five distinctive 
shapes—(1) conical, longer than the calyx-tube, ex. #. cornuta ; 
(2) conical, equal in length to the calyx-tube, ex. L. stellulata ; 
(3) nearly conical or hemispherical, shorter than the calyx-tuhe, 
ex. E. amygdalina ; (4) hemispherical, much broader than the 
calyx-tube, ex. 2. gomphocephala ; (5) depressed in the centre, 
shorter than the calyx-tube, ex. #. globulus. 
The operculum is an important factor in the discrimination of 
species, and is largely availed of by Bentham in his treatment of 
the species in the “ Fl. Austral.,” and by Mueller in his “‘Hucalypto- 
graphia,” the operculum of each species being pictorially repre- 
sented, 
