Bucania (Gastropoda) from the Ordovician of Estonia

Seven species of Bucania HALL 1847 from the Ordovician of Estonia are presented, also taking into consideration Pleistocene drift material from Germany, and their stratigraphical and geographical distributions are revised. The Middle Ordovician species Bucania latissima KOKEN 1897 and Bucania salpinx KOKEN 1897 are tentatively assigned to Megalomphala ULRICH in ULRICH & SCOFIELD 1897, while the Lower Ordovician species Bucania macera KOKEN in KOKEN & PERNER 1925 is placed in Salpingostoma ROEMER 1876. The Middle Ordovician Bucania czekanowskii (SCHMIDT 1858) and the Upper Ordovician Bucania radiata (D'EICHWALD 1856) were earlier considered conspecific, but based on study of the type material they are here considered distinct species. Salpingostoma cornu (KOKEN 1897), commonly referred to this genus because of the trema, is here transferred to Bucania. Two Upper Ordovician specimens of Bucania display wide and abruptly flaring apertures morphologically far removed from other species of the genus.