^{page 487 note 1} Amer. Journ. Sci., vol. iii, 1897.Google Scholar

^{page 487 note 2} Centralblatt Min. Geol. Palaeont., 1907, p. 129.Google Scholar

^{page 487 note 3} Zeitsch. Deutsch. geol. Ges., Bd. lxi, p. 380, 1909.Google Scholar

^{page 488 note 1} Cf. Woods, H., Cambridge Natural History, vol. Crustacea, ch. Trilobites, pp. 226, 244.Google Scholar

^{page 489 note 1} Textbook of Palœontology, Zittel, ed. Eastman, , vol. i, p. 713, 1913.Google Scholar

^{page 489 note 2} Barrande, J., Système Silurien, Trilobites, p. 616.Google Scholar

^{page 489 note 3} Geol. Mag., 1912, p. 347.Google Scholar

^{page 489 note 4} Monogr. Palæont. Soc., 1907, p. 45.Google Scholar

^{page 489 note 5} La Paléontologie Ethologique, Bruxelles, 1910, p. 417.Google Scholar

^{page 490 note 1} Reed, F. R. C., Geol. Mag., 1912, p. 202.Google Scholar

^{page 490 note 2} Cf. Reed, F. R. C., Geol. Mag., 1898, p. 446 et seqq.Google Scholar

^{page 490 note 3} Some time after this paper was finished Mr. H. H. Thomas kindly called my attention to an article on Harpes, by Rudolf Richter, in the Zoologischer Anzeiger for December, 1914, a copy of which had reached England. This author has made a very careful study of the minute structure of this genus. He shows that the ‘eyespots’ consist of biconvex lenses like those of the normal Trilobite eye, and he regards them as vestiges of a once well-developed compound eye. He also shows that the marginal suture cannot be regarded as homologous with the true facial suture.

^{page 490 note 4} Monogr. Palæont. Soc., 1907, p. 40.Google Scholar

^{page 490 note 5} Vide infra.

^{page 490 note 6} Amer. Journ. Sci., 1897, p. 183.Google Scholar

^{page 490 note 7} Op. cit., p. 387; vide also Woods, op. cit., p. 225.

^{page 490 note 8} Op. cit., p. 388.

^{page 491 note 1} Smithsonian Miscellaneous Collections, vol. lvii, p. 195, 1912.Google Scholar

^{page 491 note 2} Vide supra.

^{page 491 note 3} Op. cit., p. 392.

^{page 491 note 4} Op. cit., pp. 100, 191.

^{page 491 note 5} Cf. J. Barrande, op. cit., pp. 615, 616. Barrande decided that this association of sutures with eyes was not essential. He based his view especially upon the existence of a marginal suture in Trinucleus.

^{page 491 note 6} Woods, op. cit., p. 233.

^{page 491 note 7} Tenth Ann. Rep. U.S.G.S., 1891, p. 635.Google Scholar

^{page 491 note 8} Op. cit., p. 191.

^{page 491 note 9} Smiths. Misc. Coll., vol. liii, p. 242, 1910.Google Scholar

^{page 492 note 1} Smiths. Misc. Coll., vol. liii, p. 236, 1910.Google Scholar

^{page 492 note 2} Ibid., p. 257.

^{page 492 note 3} Op. cit., p. 100.

^{page 492 note 4} Ford, , Amer. Journ. Sci., 1877, 1881 ; Walcott, op. cit., 1891, pl. lxxxviii ; Bull. U.S.G.S., No. 30, pl. xvii, 1886.Google Scholar

^{page 492 note 5} Q.J.G.S., 1894, p. 419.Google Scholar

^{page 492 note 6} Op. cit., 1912, p. 192.

^{page 492 note 7} Op. cit., p. 194.

^{page 493 note 1} Walcott, C. D., Smiths. Misc. Coll., vol. liii, p. 14, 1908.Google Scholar

^{page 494 note 1} Neues Jahrb., 1898, p. 187.

^{page 494 note 2} Strictly that portion of Olenidæ relegated later to the Ptychoparidæ.

^{page 494 note 3} Cf. Bernard, H. M., Q.J.G.S., 1894, 1895.Google Scholar

^{page 495 note 1} Vide p. 488.

^{page 495 note 2} Walcott, C. D., Smiths, Misc. Coll., vol. liii, p. 256, 1910.Google Scholar

^{page 495 note 3} Conocephalites sulzeri, Schlot.