^{page 855 note *} Part I, Trans. Roy. Soc. Edin., vol. li, p. 761; Part II, ibid., vol. lii, p. 603; Part III, ibid., vol. lii, p. 643; Part IV, ibid., vol. lii, p. 831.

^{page 857 note *} Named Palæomyces Gordoni below (p. 868).

^{page 858 note *} Thus the specimens in fig. 5 are over 350 μ.

^{page 858 note †} Named Palæomyces Gordoni var. major below (p. 868).

^{page 860 note *} Named Palæomyces Asteroxyli below (p. 869).

^{page 860 note †} Named Palæomyces Horneæ below (p. 869).

^{page 861 note *} Named Palæomyces vestita, below (p. 869).

^{page 861 note †} Named Palæomyces agglomerata, below (p. 870).

^{page 862 note *} Named Palæomyces Simpsoni below (p. 869).

^{page 867 note *} Fossil Plants, vol. i, p. 222.

^{page 868 note *} Seward loc. cit.

^{page 871 note *} Annals of Botany, vol. i (1888), p. 315.

^{page 871 note †} Loc. cit., pl. xviii, fig. 15.

^{page 871 note ‡} Fungorum Fossilium Omnium Iconographia, Vicetiæ, MCMII.

^{page 872 note *} Ann. Bot., vol. xxxi (1917), p. 77.

^{page 872 note †} For numerous figures cf. Janse, , Ann. Jard. Bot. Buitenzorg, xiv (1897), p. 53Google Scholar, and various descriptions of mycorrhizal fungi, especially those occurring in Lycopodiaceæ and Ophioglossaceæ.

^{page 873 note *} Hornea showed corresponding structures to those to be described, but the preservation was poor.

^{page 874 note *} Weiss, , Ann. Bot., vol. xviii (1904), p. 255.CrossRefGoogle Scholar, Osborn, ibid., vol. xxiii (1909), p. 605.

^{page 880 note *} Cf. Giesenhagen, , Flora, lxxxii (1896), p. 381.Google Scholar

^{page 880 note †} Cf. M'Nicol, , Ann. Bot., vol. xxi (1907), p. 61.CrossRefGoogle Scholar

^{page 881 note *} Knowlton, Amer. Journ. Science, vol. xxxvii, p. 202; Seward, Fossil Plants, vol. i, pp. 225–226.

^{page 883 note *} Penhallow, , Ann. Bot., vol. x, p. 144, 1896.Google Scholar

^{page 884 note *} It will be sufficient to give a general reference to the diagnoses of N. Logani, N. Hickcsii, N. crassum, N. laxum, and N. tenue in Penhallow's, paper (Trans. Canad. Roy. Soc., vol. vii, 1889, p. 28)Google Scholar; to that of N. Ortoni, in a paper by the same investigator (Ann. Bot., vol. x, 1896, p. 41); and to that of N. Dechenianum, in the paper by Solms (Jahrb. d. k. preuss. Geol. Landesanstalt, 1894).

^{page 885 note *} A similar mode of preservation was met with in N. Hicksii (cf. Penhallow, loc. cit., 1889, p. 20).

^{page 885 note †} A very similar spiral marking, due to contraction and ridging of the inner layer of the cell-wall, is often met with in the cells of Laminaria. It has there been interpreted as an artefact due to drying or dehydration (cf. MrsThoday, M. G., New Phytolgist, x (1911), p. 69Google Scholar).

^{page 886 note *} This layer is described as “very thin, hardly exceeding 3 mm.” for N. Logani (Penhallow, , Trans. Canad. Roy. Soc., vol. vi, 1888, p. 38Google Scholar), and as 1·5 mm. in N. Ortoni (Penhallow, , Ann. Bot., vol. x, 1896, p. 42Google Scholar).

^{page 886 note †} Monthly Microscopical Journal, vol. viii, 1872.

^{page 887 note*} It may be noted that a recent suggestion, while emphatically dismissing comparison with the Laminariceæ, treats Nematophyton in connection with massive Fungi (Church, Thalassiophyta, p. 49 and footnote).

^{page 887 note †} Dawson's views on this point are expressed in a number of his publications (e.g., The Fossil Plants of the Devonian and Upper Silurian Formations of Canada, 1871, and The Geological History of Plants, 1888), but most clearly and recently in Penhallow, and Dawson, , Trans. Ganad. Roy. Soc., vol. vi, 1888, pp. 27–36.Google Scholar It will be remembered that these views were founded on study of the mode of occurrence of the plant as shown in the rock-sections exposed at Gaspé and the Bay des Chaleurs. Their nature may fairly be given by some extracts from the last-named paper, though the context should be consulted. “The mode of occurrence and state of preservation of the specimens seemed to make it certain that they had belonged to land-plants” (p. 27). “I also found stumps with branching roots apparently rooted in situ in the shales and argillaceous sandstones of the locality” (p. 28). “I also ascertained that these remarkable plants had probably grown in the clays and sands in which Psilophyton and other plants had been rooted, and consequently, that though probably marsh-plants they were not marine. They must have grown on low flats, probably often inundated, though whether this was with salt or fresh water is indicated merely by the negative fact that no properly marine organisms occur in the containing beds” (p. 28). “It was further found that Psilophyton princeps, P. robustius, Arthrostigma gracile, and Cordaites angustifolia were constant associates of these plants” (p. 29). In connection with the last quotation, it is to be noted that the remains referred to as Cordaites angustifolia were regarded by Dawson as of quite uncertain nature, and are even discussed as possible foliage of Nematophyton (loc. cit., p. 34). Fig. 3 in the paper from which the above extracts have been made shows a trunk of Nematophyton Logani resting on an underclay filled with Psilophyton. Fig. 4 shows another trunk embedded in a bed of shale containing Psilophyton, the bed being underlain and overlain by sandstone.

^{page 888 note *} Brit. Assoc. Rep., 1916 (Newcastle), p. 206.

^{page 888 note †} The following slides in the Kidston Collection give a complete survey of this vertical section:—

When a number of slides are mentioned, as in B 6 and A″1, they are in descending order through the bed.

^{page 890 note *} This block of the chert is preserved in the British Museum (Natural History).

^{page 895 note *} Cf. Schimper, Plant Geography, p. 386, and literature there cited.