On the basis of shell characters, we review the eight Recent and two fossil species of the fasciolariid neogastropod genus Leucozonia Gray, 1847. These are L. nassa (Gmelin, 1791), type species, from the tropical western Atlantic, a geographically variable species; L. cerata (Wood, 1828) from the tropical eastern Pacific; L. leucozonalis (Lamarck, 1822) from the western Caribbean; L. ocellata (Gmelin, 1791) from the western Atlantic; L. ponderosa Vermeij and Snyder, 1998, from Ilha Trindade, Brazil; L. rudis (Reeve, 1847) from the eastern Pacific; L. triserialis (Lamarck, 1822) from the Cape Verde Islands in the eastern Atlantic; L. tuberculata (Broderip, 1833) from the Galapagos and Cocos Islands in the eastern Pacific; L. rhomboidea (Gabb, 1873) from the Gurabo Formation (early Pliocene) of the Dominican Republic; and L. striatula Vermeij, 1997, from the Cercado (late Miocene) and basal Gurabo Formations of the Dominican Republic. We review species named as or assigned to Leucozonia. The new genus Psammostoma (type species: Mazzalina costata Dall, 1890, early Miocene, Florida) may be related to the ancestry of Leucozonia. In shell characters, Leucozonia appears to be most closely related to the Indo-West Pacific genera Latirolagena Harris, 1897, and Latirus Montfort, 1810, in the latter's narrow sense. These three genera, together with Psammostoma and several others, have in common the unusual trait of beaded or discontinuous spiral ridges (lirae) on the adaxial side of the shell's outer lip. On biogeographic grounds we argue that beaded lirae evolved at least twice in the Fasciolariidae. The labral tooth of L. nassa and six other species of Leucozonia is a derived feature within the genus and evolved independently of that in three other fasciolariid groups: Benimakia Habe, 1958; Dennantia Tate, 1888; and Opeatostoma Berry, 1958.
Genus novum: Psammostoma Vermeij & Snyder.