Phylum VI. MOLLUSCA.' 



(Malacozoa Blainville ; Saccata Hyatt.) 



The Mollusca form a well-characterised, and, on the whole, remarkably 

 homogeneous group of Invertebrates, which have existed since the earliest 

 recognised advent of life upon the globe. Their progressive modifications 

 afFord us a most important guide to the successive stages of the evolution of 

 organic life as preserved in the various geological horizons. 



The Mollusca are characterised as a group by passing through a Trocho- 



^ Literature : Adams, H. and A., The Genera of Recent Mollusca, 2 voLs. London, 1853-58. — 

 Philippi, R. A., Handbuch der Conchyliologie, Halle, 1853. — Keferstein, W., Die Malacozoa. 

 Bronn's Classen und Ordnungen des Thierreichs, vol. iii., 1862-66. — Tryon, O. W., and Pilsbry, 

 H. A., Manual of Conchology, 16 vols. Philadelphia, 1879-96. — Fischer, P., Manuel de Con- 

 chyliologie et de Paleontologie conchyliologique, 1880-87. — Woodward, S. P., Manual of the 

 Mollusca. 4th Edition, with Appendix by R. Täte, 1880. — Tryon, G. W., Stnictural and Syste- 

 matic Conchology, 3 vols. Philadelphia, 1882-84. — Ihering, H. von, Le Systeme naturel des 

 Mollusques. Bull. Sei. France, 1891, vol. xxiii. — Pelseneer, P., Introduction ä l'etude des 

 Mollusques. Brüssels, 1894. 



Soioerhy, J., Mineral Conchology of Great Britain, 7 vols. London, 1812-30. — Brocchi, G. B., 

 Conchiologia fossile subappenina, 2 vols. Milan, 1814. — Deshayes, G. P., Coquilles fossiles des 

 environs de Paris, 3 vols., 1824-37. — Goldfuss, A., Petrefacta Germaniae, 1826-40. — Conrad, T. A., 

 Fossil Shells of the Tertiary Formations of North America (1832-33) ; and Fossils of the Medial 

 Tertiary of the United States (1838-61). Reprints by G. D. Harris, \^^Z.— Morton, S. G., Synopsis 

 of the Organic Remains of the Cretaceous Group of the United States, 1834. — Philippi, R. A., 

 Enumeratio Molluscorum Siciliae, 2 vols., l^^Q-ü.—Grateloup, J. P. S., Catalogue zoologique du 

 Bassin de Gironde. Bordeaux, 1838-40. — Hall, J., Palaeontology of New York, vols. i.-viii. 

 Albany, 1847-95. — Wood, S., Monograph of the Crag Mollusca. Palaeont. Soc, 1848-56, vols. 1., 

 ii.^ — Sandherger, G. and F., Die Versteinerungen des rheinischen Schichtensystems in Nassau, 

 1850-56. — Morris and Lycett, Monograph of the Mollusca of the Great Oolite. Palaeont. Soc, 

 1850-63. — M^Coy, F., British Palaeozoic Fossils. London, 1851-55. — Pictet, F. J., and Campiche, 

 G., Description des fossiles du terrain cretace de Sainte-Croix. Paleont. Suisse, ser. 5, vols. i.-iv., 

 1858-72. — Quenstedt, F. A., Der Jura. Tübingen, 1858. — Sandherger, F., Die Conchylien des 

 Mainzer Beckens. Wiesbaden, 1860-63. — Deshayes, G. P., Description des animaux sans vertebres 

 decouverts dans le Bassin de Paris, 5 vols. Paris, 1860-66. — Loriol, P. de, Monographs of the 

 Fauna of the Upper Jura of Switzerland, Haute-Marne, Yonne, Boulogne-sur-Mer, Valßn, Tonnerre ; 

 of the Neocomian of Mt. Saleve ; the Urgonian of Landeron ; the Gault of Cosne, etc., 1861-75. — 

 Cossmann, M., Essais de paleoconchologie comparee. Paris, 1895. — Gabb, W. M., Palaeontology of 

 California, vols. i. and ii., 1864, 1869.— Idem, Topography and Geology of Santo Domingo. Trans. 

 Am. Phil. Soc, 1873, vol. xv.— Geinitz, IL B., Die Dyas. Leipzic, 1864. — Ktminck, L. G. de, 

 Faune du calcaire carbonifere de la Belgique. Ann. Mus. d'Hist. Nat. Belg., 1886, vol. vi. — M'Coy, 

 F., Synopsis of the Characters of the Carboniferous Limestone Fossils of Ireland, 1862. — Meek, 

 F. JB., Report on the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri Country. 

 U.S. Geol. Surv. Terr., 1876, vol. ix. — Waagen, W., Salt Range Fossils. Mem. Geol. Surv. India. 

 Palaeont. Indica, ser. 13, \880-9>7 . — White, C. A., Non-marine fossil Mollusca of North America. 

 3rd Ann. Rept. U.S. Geol. Survey, 1883.— Walcott, C. D., Fauna of the Lower Cambriau or 

 Olenellus Zone lOth Ann. Rept. U.S. Geol. Surv., 1890. — Whidhorne, G. F., Monograph of the 

 Devonian Fauna of the South of England. Palaeontogr. Soc, 1889-1907.— J/ee^, F. B., and 

 Worthen, A. H., Palaeontology of Illinois, 1866-75, vols. i.-vi. 



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