Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/360

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356
EXTINCT GENERA OF CONIFERÆ.

the stems, had undergone decomposition, during the interval in which they were floating between their place of growth, and that of their final submersion.

M. Ad. Brongniart enumerates forty-two species of Sigillaria, and considers them to have been nearly allied to arborescent Ferns, with leaves very small in proportion to the size of the stems, and differently disposed from those of any living Ferns. He would refer to these stems many of the numerous fern leaves of unknown species, which resemble those of existing arborescent genera of this family. Lindley and Hutton show strong reasons for considering that Sagillariæ were. Dicotyledonous plants, entirely dis¢ tiuct from Ferns, and different from anything that occurs in the existing system of vegetation.[1]

Favularia. Megaphyton. Bothrodendron. Ulodendron.[2]

The same group of fossil plants to which Lindley and Hutton have referred the genus Sigillaria, contains four other extinct genera, all of which exhibit a similar disposition of scars arranged in vertical rows, and indicating the places at which leaves, or cones, were attached to the trunk. The names of these are Favularia, Megaphyton.

  1. Pl. 56, Figs. 3. 4. 5. 6. 7.
  2. "There can be no doubt," say they, (Foss. Flora, vol. i. p. 155) "that as far as external characters go, Sigillaria approached Euphorbiæ and Cacteæ more nearly than any other plants now known, particularly in its soft texture, in its deeply channelled stems, and what is of more consequence in its scars, placed in perpendicular rows between the furrows. It is also well known that both these modern tribes, particularly the latter, arrive even now at great stature; further, it is extremely probable, indeed almost certain, that Sigillaria was a dicotyledonous plant, for no others at the present day have a true separable bark. Nevertheless, in the total absence of all knowledge of the leaves and flowers of these ancient trees, we think it better to place the genus among other species, the affinity of which is at present doubtful".