. Fossil plants : for students of botany and geology . Paleobotany. 98 LTCOPODIALES [CH. and slender acicular needles very similar to those of Firms longifolium; in L, Stemhergii (fig. 141) they are much broader and shorter. In external form as in internal structure it is often impossible to distinguish between the leaves of Lepidodendron and Sigillaria, The distinguishing features enumerated by the late M. Kenault cannot be employed, with any great degree of confidence, as diagnostic characters. In transverse section the lamina of a Lepidodendron leaf presents the same appearance as that of t
. Fossil plants : for students of botany and geology . Paleobotany. 98 LTCOPODIALES [CH. and slender acicular needles very similar to those of Firms longifolium; in L, Stemhergii (fig. 141) they are much broader and shorter. In external form as in internal structure it is often impossible to distinguish between the leaves of Lepidodendron and Sigillaria, The distinguishing features enumerated by the late M. Kenault cannot be employed, with any great degree of confidence, as diagnostic characters. In transverse section the lamina of a Lepidodendron leaf presents the same appearance as that of the Sigillarian leaves represented in fig. 142. Near the. a Fig. 142. Leaves of Sigillaria in transverse section. A, A'. Section in the Manchester University Museum (Q. 631). B, C. Sections in Dr Kidston's Collection. base the free part of the leaf is usually subrhomboidal in section with short lateral wings, a ventral keel and two stomatal grooves (fig. 142, A, B, g). The form and arrangement of sto- mata are shown in tig. 143, A, which was drawn from a piece of a leaf shown in surface-view in a section lent to me by Professor Weiss. It should, however, be pointed out that the leaf cannot be certainly identified with Lepidodendron rather than with. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Seward, A. C. (Albert Charles), 1863-1941. Cambridge : University Press
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
