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——— Beiträge zur Kenntniss Fossilen Cycadeen, Breslau.

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——— Flora Fossilis Arctica, 1868-1871.

——— on the Fossil Flora of Bovey Tracey, Phil. Trans. R.S.L., 152, p. 1039.

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——— Vegetation of the Carboniferous Period, in Mem. of Geol. Survey, ii.