. Studies in fossil botany . Paleobotany. 292 STUDIES IN FOSSIL BOTANY unassigned petrified sporangia, of Palaeozoic age, as possess an annulus or other characters indicating Filicinean affinity. In Figs. 111 and 112, examples of Fern-sporangia from the English Coal-measures are represented. In the former figure two sporangia are shown, seated side by side on a fragment of leaf, in which a vascular bundle with scalariform tracheides is present. It will be noticed that the sporangia are free from each other, and that each shows a cap-like annulus, or group of enlarged cells, in the upper part.
. Studies in fossil botany . Paleobotany. 292 STUDIES IN FOSSIL BOTANY unassigned petrified sporangia, of Palaeozoic age, as possess an annulus or other characters indicating Filicinean affinity. In Figs. 111 and 112, examples of Fern-sporangia from the English Coal-measures are represented. In the former figure two sporangia are shown, seated side by side on a fragment of leaf, in which a vascular bundle with scalariform tracheides is present. It will be noticed that the sporangia are free from each other, and that each shows a cap-like annulus, or group of enlarged cells, in the upper part. The fructi- fication is certainly not a synangic one, but might conceivably belong to some Marattiaceous Fern comparable to Angiopteris, or might equally well be compared either with Schizaeaceae or Osmund- An affinity with the Botryopterideae is, however, quite as probable (see next chapter). This fructification may be distinguished as Pteridotheca Butterworthii, after its discoverer. In Fig. 112, on the other hand, we have a section passing through a large sorus, or rather a group of sori. The plane of the section was no doubt approximately parallel to that of the fertile frond, which was highly compound and apparently of the Sphenopteris type, the. Fig. hi.—Pteridotheca ButterwortJiii. Frag- ment of a Fern - frond from the Coal- measures, in vertical section, showing two sporangia(j;«), each with an apical annulus, and containing spores. In the tissue of the leaf, part of a vascular bundle is shown, appap x 34- Will. Coll. 1871. (G. T. G.). 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 Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
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