is Lycopodiaceæ. The same view is in great part adopted in my paper. But I hesitated in absolutely referring Triplosporite to Lepidostrobus, from the very imperfect knowledge then possessed of the structure of that genus. The specimens of Lepidostrobus examined by M. Brongniart were so incomplete, that they suggested to him an erroneous view of the relation of the supposed sporangium to its supporting bractea, and of the contents of the sporangium itself they afforded him no information whatever.
In concluding my account of Triplosporite, I noticed the then very recent discovery of spores in an admitted species of Lepidostrobus by Dr. Joseph Hooker, who, aware of the interest I took in everything relating to Triplosporite, the sections and drawings of which he had seen, communicated to me a section of the specimen in which spores had been observed, but which in other respects was so much altered by decomposition, that it afforded no satisfactory evidence of the mutual relation of the parts of the strobilus. The appearances, however, were such, that I hazarded the opinion of its being generically different from Triplosporite, an opinion strengtheued by M. Brongniart's account of the origin of the sporangium.
Since the abstract of my paper was printed in the Pro- [473 ceedings of the Society, the second volume of the Memoirs of the Geological Survey of Great Britain has appeared, which contains an article entitled Remarks on the Structure and Affinities of some Lepidostrobi. The principal object of Dr. Hooker, the author of this valuable essay, is from a careful examination of a number of specimens, all more or less incomplete, or in various degrees of decomposition and consequent displacement or absolute abstraction of parts, to ascertain the complete structure or common type of the genus Lepidostrobus; but the type so deduced is in every essential point manifestly exhibited, and in a much more satisfactory manner, by the single specimen of Triplosporite. This does not lessen the value of Dr. Hooker's discovery and investigation, but it gives rise to the question whether Triplosporite, which he has not at all referred to, and therefore probably considered as not belong-
