The following paper contains a complete list of the Mollusks, collected during the travels of Messrs. Büttikofer and Sala (1879—1882), of Mr. Stampfli, sent out by Mr. Büttikofer after his return from Liberia (1884—1885), and of a second visit to that country by Büttikofer and Stampfli (1886—1887). As the principal intention of the mentioned travellers was to collect vertebrated animals, there was not much time left to bestow upon Mollusks, most of which were collected by Mr. Büttikofer in the country of Grand Cape Mount, where especially all the marine forms were obtained. Full explanations as to the visited localities are given in the introductions to the lists of Birds by Büttikofer (see: Notes Leyd. Mus. 1885, p. 129 & ff. with map; 1886, pp. 243 — 245, and 1888, p. 59—63 with map). The learned Dr. H. Dohrn of Stettin, who obtained ample collections of Liberian Mollusks from his collector Mr. Schweitzer, who explored about the same localities, has kindly assisted me in the determination of some doubtful species, while Dr. A. Brot found three new species amongst the specimens of the genus Melania.