^{page 172 note 1} Beecher, , Amer. Journ. Sci., vol. iii (1897), p. 202; and in Zittel's “Textbook of Palæontology” (English translation, 1900), p. 636.Google Scholar

^{page 172 note 2} Hall, & Clarke, : Psalæont. New York, vol. vii, pp. xxvii–xxxii.Google Scholar

^{page 173 note 1} Hall & Clarke: op. cit., p. 45.

^{page 173 note 2} Salter, : Mem. Geol. Surv., dec. ii, 1849, art. 1, p. 8.Google Scholar

^{page 173 note 3} Kayser, : “Die Fauna ält. Dev. Ablag. Harzes,” p. 33 (Abhandl. geol. spec. Kart. Preuss., Bd. ii, Heft 4, 1878).Google Scholar

^{page 173 note 4} Hall & Clarke: op. cit., p. xxxi.

^{page 173 note 5} Oehlert, : Bull. Soc. Géol. France, sér. III, vol. xvii (1889), p. 758.Google Scholar

^{page 176 note 1} Hoernes, , Jahrb. Geol. Reichsanst. Wien, Bd. xxx, Heft 4 (1880), pp. 651–686; and id.,Google Scholar Kosmos, , Jahrg. iv, Bd. viii (1880), pp. 20–32.Google Scholar

^{page 177 note 1} Reed, : Geol. Mag., Dec. V, Vol. I (1904), p. 383, Pl. XII, Fig. 2.CrossRefGoogle Scholar

^{page 177 note 2} Ibid., p. 106, Pl. V.

^{page 178 note 1} Oehlert, : Bull. Soc. Géol. France, ser. m, vol. xxiv (1896), p. 843, woodcut fig. 12.Google Scholar

^{page 178 note 2} Id.: op. cit., sér. III, vol. xvii (1889), p. 758.

^{page 178 note 3} Ibid., p. 763, pl. xviii, fig. 6.