[34] J. S. Gibbons, ibid. ii. p. 129.

[35] Bull. Soc. Linn. Nord, Abbeville, 1840, p. 150.

[36] Joly, Comptes Rendus, 1842, p. 460; compare W. A. Gain, Science Gossip, xxvii. p. 118.

[37] Von Martens, SB. Nat. Fr. Berl. 1881, p. 34.

[38] Moquin-Tandon, Moll. de France, i. p. 116.

[39] Journ. of Conch. iii. p. 321 f.; iv. p. 13; Science Goss. 1866, p. 158.

[40] Reichel, Zool. Anz. x. p. 488.

[41] Schumann, Schr. Ges. Danz. (2) vi. p. 159.

[42] Fischer and Crosse, Mexico, p. 437.

[43] Journ. de Conch. iv. p. 397, but the species observed is not mentioned.