Nicholson, H. A. (69) On the occurrence of plants in the Skiddaw Slates. Geol. Mag. vol. VI. p. 494, 1869.
Nicholson, H. A. and Etheridge, R. junr. (80) A monograph of the Silurian fossils of the Girvan district in Ayrshire. Edinburgh, 1880.
Nicholson, H. A. and Lydekker, R. (89) A manual of Palaeontology. London, 1889.
Nicol, W. (34) Observations on the structure of recent and fossil Coniferae. Edinb. New Phil. Journ. vol. XVI. p. 137, 1834.
Noll, F. (95) Lehrbuch der Botanik für Hochschulen. Strasburger, Noll, Schimper und Schenk. Jena, 1895, p. 248 (Edit. 2).
Parkinson, J. (11) Organic Remains of a former world. London, 1811. (Vol. I. 1811, vol. II. 1808, vol. III. 1811.)
Parsons, J. (1757) An account of some fossil fruits and other bodies found in the island of Sheppey. Phil. Trans. vol. L. pt. I. p. 396, 1757.
Paterson (41) Description of Pothocites Grantoni, a new fossil vegetable from the Coal Formation. Trans. Bot. Soc. Edinburgh, vol. I. p. 45, 1841.
Penhallow, D. P. (89) On Nematophyton and allied forms from the Devonian (Erian) of Gaspé and Bay des Chaleurs. Trans. R. Soc. Canada, vol. VI. sect. 4 (1888).
—— (93) Notes on Nematophyton crassum. Proc. U. S. Nat. Museum, vol. XVI. p. 115, 1893.