It was not till long after our description was taken, that we had an opportunity of seeing Mons. CAVANILLE'S most accurate and elegant work, above quoted, in which this plant is first figured and described; we have selected the most essential parts of his generic character, and adopted his specific description: there is one point, however, in which we differ from him; the part which he regards as the fifth Petal, we are inclined to consider rather as that indescribable something, called by LINNAEUS the Nectary, it is indeed of little moment whether we call it a Petal or a Nectary, but there are several reasons why, strictly speaking, we cannot regard it as a Petal: in general the number of Petals correspond with the number of the leaves of the Calyx, those of the latter are four; the base of this Nectary originates deeper than the claws of the Petals, springing in fact from the same part as the Filament, its structure, especially the lower part of it, is evidently different from that of the Petals, corresponding indeed as nearly as possible with that of the base of the filament.--_Vid._ DESCER. Mons. CAVANILLE was induced to call this plant _Lopezia_, in compliment to TH. LOPEZ, a Spaniard[1]. [Footnote 1: In honorem Licent. THOMAE LOPEZ, Burgensis, qui aliquot annos Regii Senatoris munere functus in America, CAROLO V. imperante. In patriam reversus breviarium historiae naturalis novi orbis scripsit sub titulo de tribus elementis aere, aqua, et terra, MS. apud eundem Muguozium.] DESCRIPTION OF THE LOPEZIA. ROOT annual. STALK five or six feet high, branched almost to the bottom, square, of a deep red colour, smooth towards the bottom, slightly hairy above: _Branches_ like the stalk. LEAVES alternate, ovate, pointed, toothed on the edges, more so on the larger leaves, slightly beset with soft hairs, veins prominent on the under side, usually running parallel to each other and unbranched: _Leafstalks_ hairy. FLOWERS numerous, from the alae of the leaves, growing irregularly on hairy leafy racemi, standing on long slender peduncles, which hang down as the seed-vessels are produced: in this and some others of its characters, the plant shews some affinity to the _Circaea_. CALYX: a _Perianthium_ of four leaves, sitting on the Germen, leaves narrow, concave, reddish, with green tips, the lowermost one widely separated from the others, and placed immediately under the Nectary, _fig._ 1. COROLLA four _Petals_ of a pale red colour, forming in their mode of growth the upper half of a circle, the two uppermost linear, of a deeper colour near the apex, jointed below the middle, with a small green gland on each joint, standing on short round footstalks, which are hairy when magnified, the two side Petals nearly orbicular with long narrow claws, the part between the base of the Petal and the claw of a deeper red or crimson, _fig._ 2.