[1] See especially Moseley, Nature, 1885, p. 417.

[2] Quart. Journ. Conch. i. p. 371.

[3] Manuel de Conchyliologie et de Paléontologie Conchyliologique. Dr. P. Fischer. Paris, 1887.

[4] κεφαλή, head; γαστήρ, stomach; σκάπτειν, to dig; πέλεκυς, an axe; πούς, ποδός, a foot.

[5] Also known as Lamellibranchiata, Conchifera, and Acephala.

[6] πτερόν, wing.

[7] γλῶσσα, tongue; φέρειν, to carry.

[8] λείπειν, to be wanting.

[9] ἀμφί, on both sides; νεὕρον, nerve, vessel. Some authorities regard the Amphineura as a distinct Order.

[10] πολύς, many; πλάξ, plate.

[11] πρόσω, in front. Often alluded to in the sequel as ‘operculate Gasteropoda.’

[12] κτενίδιον, a little comb.

[13] δὐω, two; mόnos, single; ὦτα, auricles; καρδία, heart.

[14] ὄπισθεν, behind.

[15] Pulmo, a lung.

[16] στὕλος, pillar; ὄμματα, eyes.

[17] The Ascoglossa are dealt with below (chap. xv.).

[18] Beudant, by very gradually changing the water, accustomed marine species to live in fresh, and fresh-water species to live in salt water.

[19] Braun, Arch. f. Naturk. Liv. (2), x. p. 102 f.

[20] Lindström, Oef. K. Vet. Förh. Stockh., 1855, p. 49.

[21] Mendthal, Schr. Ges. Königsb., xxx. p. 27.

[22] SB. K. Akad. Wiss. Wien, 1889, p. 4, but the view is not universally accepted.

[23] Not to Nassa, as has been generally held. The shape of the operculum, and particularly the teeth of the radula, show a much closer connexion with Cominella.

[24] E.g. Bouvier, Le Natural, 1889, p. 242.

[25] Köhler, Zool. Jahrb. vii. 1893, p. 1 f; Haller, Arb. Zool. Inst. Wien, x. p. 71.

[26] Plate, SB. kön. Preuss. Ak. Wiss. Berl. 1893. p. 959.

[27] E.g. Pelseneer, Bull. Sc. France Belg. xxiv. p. 347 f.

[28] E.g. Bergh, Zool. Jahrb. v. p. 1 f.

[29] Calkins, Amer. Nat. xi. p. 687.

[30] One step even further (or perhaps it should be termed a branch derivative) is seen in the genus Smaragdia, which is probably a Neritina which has resumed a purely marine habit of life.

[31] SB. Naturf. Gesell. Leipz. 1886–87, pp. 40–48.

[32] L. and F. W. Moll. of India, iv. p. 167.

[33] T. Scott, Journ. of Conch. v. p. 230.

[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.

[44] Bull. Mus. C. Z. Harv. iv. p. 378.

[45] W. Harte, Proc. Dubl. N. H. Soc. iv. p. 182.

[46] See on the whole subject of threads G. S. Tye, Journ. of Conch. i. p. 401.

[47] Zoologist, ii. p. 296; iii. p. 833; iv. p. 1216; iii. p. 1036; iv. p. 1216; iii. p. 1037.

[48] Ann. Nat. Hist. ii. 1838, p. 310.

[49] H. W. Kew, Naturalist, 1889, p. 103.

[50] Zeit. wiss. Zool. xlii. p. 203 f.

[51] Sci. Trans. R. Dubl. Soc. (2) iv. p. 520.

[52] Zoologist, iv. p. 1504; iii. p. 1038; iii. p. 943.

[53] H. W. Kew, l. c.

[54] Zoologist, xix. p. 7819.

[55] Naturalist, 1889, p. 55.

[56] H. W. Kew, l. c.

[57] W. G. Binney, Bull. Mus. C. Z. Harv. iv. p. 144.

[58] Naturalist, l. c.

[59] Science Gossip, 1885, p. 154.

[60] R. Standen, Journ. of Conch. vii. p. 197.

[61] Journ. of Conch. v. p. 43.

[62] A. Paladilhe in MS. letter.

[63] J. S. Gibbons, Quart. Journ. Conch. ii. p. 143.

[64] Bull. Mus. C. Z. Harv. iv. p. 193.

[65] l. c. p. 362.

[66] Animal Life, p. 59.

[67] Zoologist, 1861, p. 7400; Brit. Conch. i. p. 108.

[68] H. Ullyett, Science Gossip, xxii. (1886), p. 214.

[69] Descent of Man, i. p. 325, ed. 1.

[70] Amer. Nat. xv. 1881, p. 976.

[71] W. A. Gain, quoted by H. W. Kew in Naturalist, 1890, p. 307, an article to which I am much indebted.

[72] Ann. Mag. Nat. Hist. (5) xvi. p. 519.

[73] Science Gossip, 1882, pp. 237, 262.

[74] H. W. Kew, Naturalist, 1893, p. 149, another most valuable article.

[75] Garden, v. p. 201, quoted by Kew, ut sup.

[76] Kew, ut sup.

[77] Science Gossip, 1883, p. 163.

[78] T. D. A. Cockerell, Science Gossip, 1885, p. 211.

[79] Ann. Mag. Nat. Hist. (2) vi. (1850) p. 68.

[80] Ann. Mag. Nat. Hist. (2) vi. p. 489.

[81] Ibid. (3) iii. p. 448.

[82] Amer. Nat. xi. (1877) p. 100; Proc. Calif. Ac. iii. p. 329.

[83] Gaz. Med. Alger. 1865, 5th Jan. p. 9.

[84] Science Gossip, 1867, p. 40.

[85] Ann. Mag. Nat. Hist. (2) ix. p. 498.

[86] Journ. of Conch. vi. p. 101.

[87] Naturalist, 1889, p. 55.

[88] Malak. Blätt. (2) iv. pp. 43 and 221.

[89] Phil. Trans. 1854 (1856), p. 8.

[90] Naturalist, 1891, p. 75 f.; Conchologist, ii. 1892, p. 29.

[91] Taylor, Journ. of Conch. 1888, p. 299.

[92] See Tennent’s Ceylon, i. p. 221, ed. 5.

[93] W. A. Gain, Naturalist, 1889, p. 55; Brockmeier, Nachr. Deutsch. Malak. Gesell. xx. p. 113.

[94] Ann. Mag. Nat. Hist. (2) ix. p. 498.

[95] Journ. Conch. vii. 1893, p. 158 f.

[96] I succeeded in hatching out eggs of Helix aspersa, during the very warm summer of 1893, in 17 days.

[97] Nachr. Deutsch. Malak. Gesell. xx. p. 146.

[98] Raymond, Nautilus, iv. p. 6.

[99] Quoted by Oehlert, Rév. Sc. xxxviii. p. 701.

[100] Animal Life, Intern. Scientif. Ser. ed. 1, p. 395.

[101] Zoologist, 1886, p. 491.

[102] Thomas, quoted by Jeffreys, Brit. Conch. i. p. 30.

[103] Journ. of Conch. iv. p. 117.

[104] Rev. L. Jenyns, Observations in Nat. Hist. p. 318.

[105] Id. ib. p. 319.

[106] Further detailed examples will be found in Kew, The dispersal of Shells, pp. 5–26.

[107] P. Z. S. 1888, p. 358.

[108] W. A. Gain, Naturalist, 1889, p. 58.

[109] Das Wetter, Dec. 1892. Another case is recorded in Amer. Nat. iii. p. 556.

[110] Zoologist, x. p. 3430.

[111] Science Gossip, 1888, p. 281.

[112] Lecoq, Journ. de Conch. ii. p. 146.

[113] Bouchard-Chantereaux, Ann. Sci. Nat. Zool. (4) xvi. (1861) p. 197.

[114] Forel, Ann. Sci. Nat. (3) xx. p. 576; Bretonnière, Comptes Rendus, cvii. p. 566.

[115] Brit. Mus. Collection.

[116] Thomas, quoted by Récluz in Journ. de Conch. vii. 1858, p. 178.

[117] Nat. Hist. of Ceylon, p. 382. See also T. L. Taylor, Rep. Brit. Ass. for 1848, p. 82.

[118] Dr. R. E. Grant, Edinb. Phil. Journ. xiv. p. 188.

[119] Rep. Brit. Ass. for 1848, p. 80. The statement is confirmed by Rossmässler.

[120] Journ. of Conch. iv. p. 118.

[121] Zoologist, 1887, p. 29.

[122] Arch. Zool. Exp. Gén. (2) v. p. 459 f.

[123] Journ. of Conch. iii. p. 277; compare W. M. Webb, Zoologist, 1893, p. 281.

[124] Bull. Mus. Comp. Zool. Harv. iv. p. 85.

[125] Erjavec, Nachr. Deutsch. Malak. Gesell. 1885, p. 88.

[126] Crosse, Journ. de Conch. (3) xiv. (1874) p. 223.

[127] C. Wright, Zoologist, 1869, p. 1700.

[128] W. V. Legge, Zoologist, 1866, p. 190.

[129] Blackwall, Researches, p. 139.

[130] Barrow, Travels in South Africa, ii. p. 67.

[131] Loch Creran, p. 102.

[132] Cordeaux, Zoologist, 1873, p. 3396.

[133] Amer. Nat. xii. p. 695; Science Gossip, 1865, p. 79.

[134] Journ. Trent. N. H. Soc. 1887, p. 58.

[135] Ann. Nat. Hist. iii. 1893, pp. 238, 239.

[136] Rev. Nat. Sc. Ouest, 1891, p. 261.

[137] Petit de la Saussaye, Journ. de Conch. iii. p. 97 f.

[138] J. W. Williams, Science Gossip, 1889, p. 280.

[139] Noack, Zool. JB. ii. p. 254.

[140] La Nature, xv. (2) p. 46.

[141] François, Arch. Zool. Exp. Gén. (2) ix. p. 240.

[142] A. Lang, Ber. Naturf. Ges. Freib. vi. 1892, p. 81.

[143] A. P. Thomas, Q. J. Micr. Sc. N. S. xxiii. (1883) p. 99.

[144] H. Woodward, P. Z. S. 1886, p. 176.

[145] W. E. Collinge, Zoologist, 1890, p. 467.

[146] Proc. Linn. Soc. N. S. Wales, ix. p. 944.

[147] Zoologist, xviii. (1860) p. 7136.

[148] A. Adams, Samarang, vol. ii. Zoology, p. 357.

[149] In Thomson’s British New Guinea, p. 283.

[150] Animal Life, p. 395. It should be mentioned that Von Möllendorff (Ber. Senck. Ges. 1890, p. 198) ridicules the whole theory.

[151] Von Martens, SB. Nat. Fr. Berl. 1891, p. 83.

[152] Von Martens, ibid. 1887, p. 183.

[153] SB. Nat. Gesell. Leipz. xiii.-xiv. p. 45.

[154] Garstang, Journ. Mar. Biol. Ass. N. S. i. p. 432; Giard, Bull. Sci. Fr. Belg. 1888, p. 502 f.

[155] Nautilus, vi. 1892, p. 90.

[156] R. F. Scharff, Sci. Trans. R. Dubl. Soc. (2) iv. p. 553 f.

[157] Q. Journ. Micr. Sci. N. S. xxxi. (1890) p. 41 f.

[158] A detailed account is given in Proc. Liverp. Biol. Soc. iv. (1890) pp. 150–163.

[159] Journ. Mar. Biol. Ass. N. S. i. p. 418 f.

[160] Garstang, Conchologist, ii. p. 49.

[161] Hecht, Comptes Rendus, cxv. p. 746.

[162] Conchologist, ii. p. 130.

[163] Described as a Cypraea, but no doubt an Ovula or Pedicularia: CB. Bakt. Par. v. p. 543.

[164] Von Graff, Z. wiss. Zool xxv. p. 124.

[165] Proc. Amer. Phil. Soc. xxv. p. 231.

[166] Ergeb. naturw. Forsch. Ceylon, abstr. in Journ. Roy. Micr. Soc. (2) vi. p. 412.

[167] Voyage of the Samarang, Moll. p. 69, Pl. xi. f. 1; p. 47, Pl. xvii. f. 5.

[168] E. A. Smith, Ann. Mag. Nat. Hist. (6) iii. p. 270.

[169] Journ. de Conch. (3) xxix. p. 101.

[170] Zool. Jahrb. Abth. f. Syst. v. p. 619.

[171] See especially Semper, Animal Life, Ed. 1, p. 351.

[172] Gould, Moll. of U.S. expl. exped. 1852, p. 207 (St. acicula, from Fiji).

[173] Stimpson, Proc. Bost. Soc. N. H. vi. 1858, p. 308.

[174] Pidgeon, Nature, xxxix. p. 127.

[175] W. Anderson Smith, Loch Creran, p. 46.

[176] Smart, Journal of Conch. v. p. 152.

[177] Animal Life, p. 351.

[178] Journ. of Conch. vi. 1891, p. 399.

[179] Ann. Mag. N. H. (6) vii. p. 276.

[180] Stimpson, quoted by Jeffrey’s Brit. Conch. ii. 194.

[181] Stimpson, Journ. Bost. Soc. N. H. vi. 1857, p. 48.

[182] E. H. Matthews, Conchologist, ii. p. 144.

[183] Thus Limnaea involuta, which is almost universally regarded as a good and distinct species, has been held to be no more than a variety of L. peregra produced by locality; see Zoologist, 1889, p. 154.

[184] J. W. Taylor, Journ. of Conch. v. p. 289, an interesting article, with many useful references.