The holotype of Conus pusio Sowerby I, 1834, is traced in the National Museum of Wales. This specimen also represents the holotype of C. melvilli Sowerby III, 1879, which fact makes both taxa objective synonyms. Since the name C. pusio is preoccupied by Hwass, 1792, the valid name for the species is C. melvilli. The holotype is a unique specimen; although mentioned from Key West, its locality is unknown. Conus melvilli “Sowerby” in Perry, 1939, from Florida was renamed C. perryae Clench, 1942.