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Rh the dilated, and in a few cases obscurely lobed, apex of which the sessile ovarium is placed. If this be a correct view of the structure of Euphorbia, it may be expected that the true filament or upper joint of what has commonly been called filament, should, as in other plants, be produced subsequent to the distinct formation of the anthera, which consequently will be found at first sessile on the lower joint or peduncle, after that has attained nearly its full length; and accordingly this proves to be the case in such species as I have examined. Additional probability is given to this view by the difference existing between the surfaces [557 of the two joints in some species. I consider it, however, as absolutely proved by an unpublished genus of this order, having an involucrum nearly similar to that of Euphorbia, and like it, inclosing several fasciculi of monandrous male flowers, surrounding a single female; but which, both at the joint of the supposed filament, and at that by which the ovarium is connected with its pedicellus, has an obvious perianthium, regularly divided into lobes.

UMBELLIFERÆ. This order may be considered as chiefly European, having its maximum in the temperate climates of the northern hemisphere; in the corresponding southern parallels it is certainly much less frequent, and within the tropics very few species have been observed. In Terra Australis the Umbelliferæ, including a few Araliæ, which belong at least to the same natural class, exceed 50 species. The greater part of these are found in the principal parallel, in which also those genera deviating most remarkably from the usual structure of the order occur. The most singular of these is Actinotus of Labillardière, which differs from the whole order in having a single ovulum in the unimpregnated ovarium. A second genus, which I shall hereafter publish with the name of Leucolæna, is worthy of notice on account of the great apparent differences of inflorescence existing amongst its species; which agree in habit,