Description of a new species of Calliostoma (Gastropoda, Calliostomatidae) from Southeastern Brazil

Abstract. Calliostoma tupinamba isa new species from Southeastern Brazil, ranging from southern Rio de Janeiro to northern São Paulo, and found only on coastal islands, on rocks and sessile invertebrates at 3 to 5 meters of depth. Shell and soft part morphology is described here in detail. Calliostoma tupinamba is mainly characterized by a depressed trochoid shell; eight slightly convex whorls; a sharply suprasutural carina starting on the third whorl and forming a peripheral rounded keel; and a whitish, funnel-shaped and deep umbilicus, measuring about 5%–10% of maximum shell width. Calliostoma tupinamba resembles Calliostoma bullisi Clench & Turner, 1960 in shape, but differs from it in being taller and wider, having a smaller umbilicus and lacking a strong and large innermost spiral cord at its base. Finally, an identification key of Brazilian Calliostoma species is presented.