. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. frovn the Quebec Group of Point Levis. 135 and often curved, witli their convexities directed towards the base of the frojid. Cellules undetermined. Surface smooth. Length of the largest frond observed (not a perfect one) a little over two inches, breadth a little above the base about one fifth of an inch, breadth at summit nearly two inches (fig. 1, a^h). Fie:. Dictyonema grandis, Nich.: a, fragment of a frond, natural size, showing the rapid divergence and bifurcation of
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. frovn the Quebec Group of Point Levis. 135 and often curved, witli their convexities directed towards the base of the frojid. Cellules undetermined. Surface smooth. Length of the largest frond observed (not a perfect one) a little over two inches, breadth a little above the base about one fifth of an inch, breadth at summit nearly two inches (fig. 1, a^h). Fie:. Dictyonema grandis, Nich.: a, fragment of a frond, natural size, showing the rapid divergence and bifurcation of the branches; h, a fragment, enlarged, to show the fenestrules and connecting filaments. There can be no doubt as to the close alliance which subsists between this species and the Dictyonema Murrayi described by Hall from the shales of Point L^vis (Grapt. Quebec Group, p. 138, pi. XX. figs. 6, 7). The following are the characters ascribed to the latter:—"Frond very large, gradually spreading from its origin. Branches strong, width from 5 to 8 hundredths of an inch, infrequently bifurcating ; divisions little diverging, the interspaces being little wider than the branches. The fenestrules have a width of 8 by a length of 11 hundredths of an inch. The connecting filaments are wide at their origin or union with the branch, and slender in the middle; from about one third to one half as wide as the branches. Cellules un- determined. Surface ; When we compare the above description with that of the present species, the latter appears to be clearly separated by the conical form of the frond, and the rapid divergence and frequent bifurcation of the branches, whilst the fenestrules are almost always markedly wider than they are long, the reverse of this obtaining in D. Murrayi. These peculiarities along with some other, minor differences, which will be sufficiently. Please note that these images are extracted from scanned page images that may have been digitally enhan
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