Comparative morphology of Leucozonia from Brazil (Neogastropoda: Buccinoidea: Fasciolariidae)

The morphology of the fasciolariid gastropods Leucozonia nassa (Gmelin, 1791), L. ocellata (Gmelin, 1791) and L. ponderosa Vermeij and Snyder, 1998 from Brazil is described. Examination of several shells from the oceanic island of Trindade, off southeastern Brazil confirmed the conchological differences between L. ponderosa and L. nassa. In addition, the first occurrence of L. ponderosa is documented from the Fernando de Noronha Archipelago, off northeastern Brazil. The anatomy of L. ponderosa is shown to be identical to L. nassa, except for minor radular features; however, the male genital system was not examined because of the lack of male specimens of L. ponderosa available for study. Leucozonia ocellata differs from L. nassa and L. ponderosa in having a proportionally smaller seminal receptacle and bursa copulatrix, a rhynchostome with lip-like margins, a curved anterior esophagus, and a cement gland with a posteriorly folded branch. Anatomic characters of the species studied here agree with the previous descriptions of fasciolariid anatomy.