Allusion has been made elsewhere to the profusion and variety of shells which abound in the seas and inland waters of Ceylon[1], and to the habits of the Moormen, who monopolise the trade of collecting and arranging them in satin-wood cabinets for transmission to Europe. But, although naturalists have long been familiar with the marine testacea of this island, no successful attempt has yet been made to form a classified catalogue of the species; and I am indebted to the eminent conchologist, Mr. Sylvanus Hanley, for the list which accompanies this notice of those found in the island. [Footnote 1: See Vol. II. P. ix. ch. v.] In drawing it up, Mr. Hanley observes that he found it a task of more difficulty than would at first be surmised, owing to the almost total absence of reliable data from which to construct it. Three sources were available: collections formed by resident naturalists, the contents of the well-known satin-wood boxes prepared at Trincomalie, and the laborious elimination of locality from the habitats ascribed to all the known species in the multitude of works on conchology in general. But, unfortunately, the first resource proved fallacious. There is no large collection in this country composed exclusively of Ceylon shells. And the very few cabinets rich in the marine treasures of the island having been filled as much by purchase as by personal exertion, there is an absence of the requisite confidence that all professing to be Singhalese have been actually captured in the island and its waters. The cabinets arranged by the native dealers, though professing to contain the productions of Ceylon, include shells which have been obtained from other islands in the Indian seas; and books, probably from these very facts, are either obscure or deceptive. The old writers content themselves with assigning to any particular shell the too-comprehensive habitat of "the Indian Ocean," and seldom discriminate between a specimen from Ceylon and one from the Eastern Archipelago or Hindustan. In a very few instances, Ceylon has been indicated with precision as the habitat of particular shells, but even here the views of specific essentials adopted by modern conchologists, and the subdivisions established in consequence, leave us in doubt for which of the described forms the collective locality should be retained. Valuable notices of Ceylon shells are to be found in detached papers, in periodicals, and in the scientific surveys of exploring voyages. The authentic facts embodied in the monographs of Reeve, Kuster, Sowerby, and Kienn, have greatly enlarged the knowledge of the marine testacea; and the land and fresh-water mollusca have been similarly illustrated by the contributions of Benson and Layard in the _Annals of Natural History_.