BOTANICAL AND GEOLOGICAL. 719
' Geological Society's Transactions/ there can be no doubt ; but the only "additions" indicated in the notes to this, the third edition, appear to be the following :
Mr. Robert Brown has ascertained, by examination of a trunk of Cycadites microphyltus, from Portland, the ex- istence of scalariform vessels without discs, in the mature trunk ; a point in which, he informs me, these fossils agree with the American portion of the order Cycadece, though, in other respects, they bear a greater resemblance to the African and Australian species. Mr. Brown observes further, that the order Cycadea presents but one genus in America, namely, the Zamia, on which this genus was originally founded, and to which it has been recently re- stricted ; and that the coincidence in the structure of the scalariform vessels in the trunk of this Zamia of the New World, with that of the fossil Cycadites of Europe, is very remarkable. Buckland's Bridyeioater Treatise, new edition, 1858, vol. i, pp. 461, 462.
Mr. Robert Brown has noticed in the cellular tissue of a silicified trunk of Cycadites, portions of chalcedony bear- ing the form of extravasated gum within the trunks of recent Cycadece. He has also recognised spiral vessels in the laminated woody circle of a mature trunk of fossil Cycadites, and also in the laminated circle within a silici- fied bud of the same, near its origin. Ibid., vol. ii, p. 102.
Mr. [now Sir] R. I. Murchison, in a paper on the " Fossils found at CEningen," says —
" Mr. R. Brown has discovered that among these plants, one is almost indistinguishable in the leaf from the Acer villosum, a species of maple brought from Nepaul by Dr. Wallich." Geol. Trans., 2nd ser., vol. hi, p. 287 (1835).
Mr. Horner, in a note to his paper " On the Geology of the Environs of Bonn," says —
" I visited the lignite deposit at Friesdorf, in September, 1835, in company with Mr. Robert Brown, when he col- lected several specimens of the vegetable remains. lie in-
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