^{page 254 note *} The Old Red Sandstone, p. 124, pl. vii, figs. 3–7.

^{page 254 note †} M'Nab, , Trans. Bot. Soc. Edm., vol. x, p. 312Google Scholar. Kidston, and Lang, , Trans. Roy. Soc. Edin., vol. liii, p. 409Google Scholar.

^{page 254 note ‡} Footprints of the Creator, figs. 61, 62.

^{page 254 note §} Testimony of the Rocks, figs. 12, 120.

^{page 254 note ∥} See Geikie, “On the Old Red Sandstone of Western Europe,” Trans. Roy. Soc. Edin., vol. xxviii, p. 445,Google Scholar and Hugh Miller's works.

^{page 261 note *} Loc. cit., p. 14, Taf. 4, figs. 10, 11.

^{page 262 note *} Footprints of the Creator, figs. 61a, 62a.

^{page 262 note †} Q. J. Geol. Soc., vol. xiv, pl. v, figs. 3, 4, and 6.

^{page 262 note ‡} Trans. Edin. Geol. Soc., vol. iii, p. 150.

^{page 262 note †} Journ. of Bot., N.S., vol. ii (1873), p. 323Google Scholar.

^{page 262 note ∥} Canad. Rec. Sci., vol. v, pp. 1–13.

^{page 262 note ¶} It is desirable to state explicitly that there is, at present, no specimen establishing the occurrence of Psilophyton princeps in the Middle Old Red Sandstone of Scotland. This well-characterised species is so far only known from the Strathmore Beds in the Lower Old Red Sandstone of Scotland. From its occurrence in Middle Devonian rocks in Germany and Canada there is, of course, no improbability in its being discovered in the Middle Old Red Sandstone. But no specimen, so far as I know, establishes a clear record of it, although the name has frequently been loosely applied to the remains under consideration here.

^{page 262 note **} Trans. Roy. Soc. Edin., vol. xl, pp. 759, 760.

^{page 262 note ‡} Potonié and Bernard, Flore Devonienne de l'etage H. de Barrande, p. 14ff.

^{page 262 note ‡‡} Kraüsel, R., and Weyland, H., Senckenbergiana, Bd. v, pp. 154–184Google Scholar.

^{page 262 note §§} Bergens Museums Aarbok, 1914–15, Nr. 9.

^{page 263 note *} Kraüsel and Weyland, loc. cit.

^{page 263 note †} Kungl. Svensk. Vetenskapsakad. Handlingar, Bd. lvii, Nr. 1, pp. 23, 24.

^{page 263 note ‡} The Old Red Sandstone, pl. vii, fig 3; Testimony of the Rocks, fig. 119.

^{page 264 note *} Hugh Miller's words may be quoted (Footprints of the Creator, 20th ed., p. 186): “A smooth-stemmed fucoid, existing on the stone in most cases as a mere film, in which, however, thickly set longitudinal fibres are occasionally traceable,”

^{page 265 note *} Annals of Botany, vol. xxxvii, p. 379 ff.

^{page 267 note *} Sitzb. Ak. Wiss. Wien, vol. lxxxiv, Taf. 4, fig. 7.

^{page 267 note †} Loc. cit., figs. 1–6.

^{page 267 note ‡} Devonian Floras, p. 32, fig. 14.

^{page 270 note *} Cf. especially Kidston, and Bennie, , “On the Occurrence of Spores in the Carboniferous Formation of Scotland,” Proc, Roy. Phys. Soc. Edin., vol. ix, p. 82Google Scholar ff.

^{page 271 note *} This suggestion has been confirmed by the study of a specimen ofHostimella (Ptilophyton) Thomsoni, collected in August 1925.

^{page 272 note *} Footprints of the Creator, fig. 63.

^{page 272 note †} Loc. cit., p. 188.

^{page 274 note *} Q. J. Geol. Soc., vol. xiv, p. 74, pl. v, figs, 7a, 7b.

^{page 278 note *} These numbers refer to the writer's collection of pre-carboniferous plants. They will be traceable if the specimens are later transferred to a museum collection.