[192]. Studies in Evolution, 1901, pp. 197–225; Geol. Mag. 1902, p. 152. Walcott, Proc. Biol. Soc. Washington, ix., 1894, p. 89.
[193]. Syst. Sil. Bohême, i., 1852, pp. 257–276.
[194]. American Geologist, xx., 1897, p. 34.
[195]. Proc. R. Irish Acad. xxiv., 1903, p. 332, and Quart. Journ. Micr. Sci. xlix., 1906, p. 469.
[196]. This has received some support from H. Milne Edwards, Ann. Sci. Nat. Zool. (6), xii., 1881, p. 33; H. Woodward, Quart. Journ. Geol. Soc. xxvi., 1870, p. 487, and vol. 1., 1894, p. 433; Bernard, ibid. vol. 1. p. 432.
[197]. Kingsley does not admit this relationship, and regards the Trilobita as a group quite distinct from all other Crustacea. See American Naturalist, xxviii., 1894, p. 118, and American Geologist, xx., 1897, p. 33.
[198]. Zittel states that Apus appears first in the Trias.
[199]. Monogr. Brit. Trilobites, 1864, p. 2.
[200]. “A Natural Classification of Trilobites,” Amer. Jour. Sci. (4), iii., 1897, pp. 89–106, 181–207. Reprinted in Beecher’s Studies in Evolution, 1901, p. 109. A classification based on the character of the pygidium has been proposed by Gürich, Centralbl. für Min. Geol. u. Pal. 1907, p. 129. A classification based on the minute structure of the test has been given by Lorenz, Zeitschr. d. deutsch. geol. Gesellsch. lviii., 1906, p. 56.
[201]. Neues Jahrb. für Min. Geol. u. Pal. 1898, i. p. 187.